Discussion:
[PATCH] s390/oprofile: Remove deprecated create_workqueue
(too old to reply)
Bhaktipriya Shridhar
2016-06-07 21:59:12 UTC
Permalink
Raw Message
A dedicated workqueue has been used since the workqueue hws_wq with
workitem &cb->worker, is involved in hardware based sampling
on System z processors.

Since, these are long-running work items and aren't involved in memory
reclaim in any way, system_long_wq has been used.

Signed-off-by: Bhaktipriya Shridhar <***@gmail.com>
---
arch/s390/oprofile/hwsampler.c | 21 +++------------------
1 file changed, 3 insertions(+), 18 deletions(-)

diff --git a/arch/s390/oprofile/hwsampler.c b/arch/s390/oprofile/hwsampler.c
index ff9b4eb..8b16bb8 100644
--- a/arch/s390/oprofile/hwsampler.c
+++ b/arch/s390/oprofile/hwsampler.c
@@ -42,7 +42,6 @@ static DEFINE_MUTEX(hws_sem_oom);
static unsigned char hws_flush_all;
static unsigned int hws_oom;
static unsigned int hws_alert;
-static struct workqueue_struct *hws_wq;

static unsigned int hws_state;
enum {
@@ -189,8 +188,7 @@ static void hws_ext_handler(struct ext_code ext_code,
inc_irq_stat(IRQEXT_CMS);
atomic_xchg(&cb->ext_params, atomic_read(&cb->ext_params) | param32);

- if (hws_wq)
- queue_work(hws_wq, &cb->worker);
+ queue_work(system_long_wq, &cb->worker);
}

static void worker(struct work_struct *work);
@@ -566,15 +564,12 @@ int hwsampler_deactivate(unsigned int cpu)
} else {
hws_flush_all = 1;
/* Add work to queue to read pending samples.*/
- queue_work_on(cpu, hws_wq, &cb->worker);
+ queue_work_on(cpu, system_long_wq, &cb->worker);
}
}
}
mutex_unlock(&hws_sem);

- if (hws_wq)
- flush_workqueue(hws_wq);
-
return rc;
}

@@ -740,7 +735,7 @@ static void worker_on_finish(unsigned int cpu)
continue;
if (!cb->finish) {
cb->finish = 1;
- queue_work_on(i, hws_wq,
+ queue_work_on(i, system_long_wq,
&cb->worker);
}
}
@@ -997,9 +992,6 @@ int hwsampler_setup(void)
goto setup_exit;

rc = -EINVAL;
- hws_wq = create_workqueue("hwsampler");
- if (!hws_wq)
- goto setup_exit;

register_cpu_notifier(&hws_cpu_notifier);

@@ -1049,9 +1041,6 @@ int hwsampler_shutdown(void)
if (hws_state == HWS_DEALLOCATED || hws_state == HWS_STOPPED) {
mutex_unlock(&hws_sem);

- if (hws_wq)
- flush_workqueue(hws_wq);
-
mutex_lock(&hws_sem);

if (hws_state == HWS_STOPPED) {
@@ -1059,10 +1048,6 @@ int hwsampler_shutdown(void)
hws_alert = 0;
deallocate_sdbt();
}
- if (hws_wq) {
- destroy_workqueue(hws_wq);
- hws_wq = NULL;
- }

unregister_external_irq(EXT_IRQ_MEASURE_ALERT, hws_ext_handler);
hws_state = HWS_INIT;
--
2.1.4
kbuild test robot
2016-06-07 23:29:00 UTC
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Hi,

[auto build test ERROR on s390/features]
[also build test ERROR on v4.7-rc2 next-20160607]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url: https://github.com/0day-ci/linux/commits/Bhaktipriya-Shridhar/s390-oprofile-Remove-deprecated-create_workqueue/20160608-060615
base: https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git features
config: s390-default_defconfig (attached as .config)
compiler: s390x-linux-gnu-gcc (Debian 5.3.1-8) 5.3.1 20160205
reproduce:
wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=s390
arch/s390/oprofile/hwsampler.c:1151:6: error: 'hws_wq' undeclared (first use in this function)
if (hws_wq)
^
arch/s390/oprofile/hwsampler.c:1151:6: note: each undeclared identifier is reported only once for each function it appears in

vim +/hws_wq +1151 arch/s390/oprofile/hwsampler.c

ec6a3df1 Heinz Graalfs 2011-01-21 1145 cb->stop_mode = 1;
ec6a3df1 Heinz Graalfs 2011-01-21 1146 tmp_rc = stop_sampling(cpu);
ec6a3df1 Heinz Graalfs 2011-01-21 1147 if (tmp_rc)
ec6a3df1 Heinz Graalfs 2011-01-21 1148 rc = tmp_rc;
ec6a3df1 Heinz Graalfs 2011-01-21 1149 }
ec6a3df1 Heinz Graalfs 2011-01-21 1150
ec6a3df1 Heinz Graalfs 2011-01-21 @1151 if (hws_wq)
ec6a3df1 Heinz Graalfs 2011-01-21 1152 flush_workqueue(hws_wq);
ec6a3df1 Heinz Graalfs 2011-01-21 1153
ec6a3df1 Heinz Graalfs 2011-01-21 1154 mutex_lock(&hws_sem);

:::::: The code at line 1151 was first introduced by commit
:::::: ec6a3df1c008d9e8664e53b0363f6847c5c0dc3f oprofile, s390: Add support for hardware based sampling on System z processors

:::::: TO: Heinz Graalfs <***@linux.vnet.ibm.com>
:::::: CC: Robert Richter <***@amd.com>

---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
Heiko Carstens
2016-06-09 09:00:56 UTC
Permalink
Raw Message
Post by Bhaktipriya Shridhar
A dedicated workqueue has been used since the workqueue hws_wq with
workitem &cb->worker, is involved in hardware based sampling
on System z processors.
Since, these are long-running work items and aren't involved in memory
reclaim in any way, system_long_wq has been used.
---
arch/s390/oprofile/hwsampler.c | 21 +++------------------
1 file changed, 3 insertions(+), 18 deletions(-)
Besides that your patch doesn't compile... ;)

Removing the flush_workqueue is probably wrong, since the oprofile module
can now be unloaded while there could still be a reference to a worker
structure owned by the oprofile module.

However I'm wondering if we shouldn't simply remove at least the s390
specific hwswampler code from the oprofile module. This would still leave
the common code timer based sampling mode for oprofile working on s390.

It looks like the oprofile user space utility nowadays (since 2012) uses
the kernel perf interface instead of the oprofile interface anyway, if
present. So the oprofile module itself doesn't seem to have too many users
left.

Any opinions?
Post by Bhaktipriya Shridhar
- if (hws_wq)
- flush_workqueue(hws_wq);
-
mutex_lock(&hws_sem);
if (hws_state == HWS_STOPPED) {
@@ -1059,10 +1048,6 @@ int hwsampler_shutdown(void)
hws_alert = 0;
deallocate_sdbt();
}
- if (hws_wq) {
- destroy_workqueue(hws_wq);
- hws_wq = NULL;
- }
unregister_external_irq(EXT_IRQ_MEASURE_ALERT, hws_ext_handler);
hws_state = HWS_INIT;
--
2.1.4
Robert Richter
2016-06-13 16:29:14 UTC
Permalink
Raw Message
Heiko,
Post by Heiko Carstens
However I'm wondering if we shouldn't simply remove at least the s390
specific hwswampler code from the oprofile module. This would still leave
the common code timer based sampling mode for oprofile working on s390.
It looks like the oprofile user space utility nowadays (since 2012) uses
the kernel perf interface instead of the oprofile interface anyway, if
present. So the oprofile module itself doesn't seem to have too many users
left.
Any opinions?
yes, the kernel driver is not necessary for oprofile userland for a
while now. There is no ongoing development any longer, most patches
are due to changes in the kernel apis.

So if there is code that needs a larger rework due to other kernel
changes and there is no user anymore, I am fine with removing the code
instead of reworking it. I still would just keep existing code as long
as we can keep it unchanged (some like the lightwight of oprofile,
esp. in the embedded space). If there is a user of the code, a
Tested-by would be good for new code changes.

If there are users of the hwswampler, speak up now. Else, let's just
remove it.

-Robert
William Cohen
2016-06-13 20:44:19 UTC
Permalink
Raw Message
Post by Robert Richter
Heiko,
Post by Heiko Carstens
However I'm wondering if we shouldn't simply remove at least the s390
specific hwswampler code from the oprofile module. This would still leave
the common code timer based sampling mode for oprofile working on s390.
It looks like the oprofile user space utility nowadays (since 2012) uses
the kernel perf interface instead of the oprofile interface anyway, if
present. So the oprofile module itself doesn't seem to have too many users
left.
Any opinions?
yes, the kernel driver is not necessary for oprofile userland for a
while now. There is no ongoing development any longer, most patches
are due to changes in the kernel apis.
So if there is code that needs a larger rework due to other kernel
changes and there is no user anymore, I am fine with removing the code
instead of reworking it. I still would just keep existing code as long
as we can keep it unchanged (some like the lightwight of oprofile,
esp. in the embedded space). If there is a user of the code, a
Tested-by would be good for new code changes.
If there are users of the hwswampler, speak up now. Else, let's just
remove it.
-Robert
Hi,

As Robert mentioned the user-space oprofile code that would have used the oprofile device driver was removed around August 2014 in preparation for oprofile-1.0. The operf command which uses the kernel perf infrastructure and does not need for the oprofile kernel driver has been in oprofile since August of 2012. For some architectures it would make sense to simplify things by eliminate the oprofile kernel driver.

-Will Cohen
Heiko Carstens
2016-06-14 05:36:08 UTC
Permalink
Raw Message
Post by Robert Richter
Heiko,
Post by Heiko Carstens
However I'm wondering if we shouldn't simply remove at least the s390
specific hwswampler code from the oprofile module. This would still leave
the common code timer based sampling mode for oprofile working on s390.
It looks like the oprofile user space utility nowadays (since 2012) uses
the kernel perf interface instead of the oprofile interface anyway, if
present. So the oprofile module itself doesn't seem to have too many users
left.
Any opinions?
yes, the kernel driver is not necessary for oprofile userland for a
while now. There is no ongoing development any longer, most patches
are due to changes in the kernel apis.
So if there is code that needs a larger rework due to other kernel
changes and there is no user anymore, I am fine with removing the code
instead of reworking it. I still would just keep existing code as long
as we can keep it unchanged (some like the lightwight of oprofile,
esp. in the embedded space). If there is a user of the code, a
Tested-by would be good for new code changes.
If there are users of the hwswampler, speak up now. Else, let's just
remove it.
Ok, so I'll wait a week or so and remove the code if nobody speaks up. Is
it ok for you if I add the patch to the s390 kernel tree?
The patch would only remove s390 specific architecture code.

I have this pending:

s390/oprofile: remove hardware sampler support

Remove hardware sampler support from oprofile module.

The oprofile user space utilty has been switched to use the kernel
perf interface, for which we also provide hardware sampling support.

In addition the hardware sampling support is also slightly broken: it
supports only 16 bits for the pid and therefore would generate wrong
results on machines which have a pid >64k.

Also the pt_regs structure which was passed to oprofile common code
cannot necessarily be used to generate sane backtraces, since the
task(s) in question may run while the samples are fed to oprofile.
So the result would be more or less random.

However given that the only user space tools switched to the perf
interface already four years ago the hardware sampler code seems to be
unused code, and therefore it should be reasonable to remove it.

The timer based oprofile support continues to work.

Signed-off-by: Heiko Carstens <***@de.ibm.com>

Documentation/kernel-parameters.txt | 2 -
arch/s390/oprofile/Makefile | 1 -
arch/s390/oprofile/hwsampler.c | 1178 --------------------------------
arch/s390/oprofile/hwsampler.h | 63 --
arch/s390/oprofile/init.c | 489 -------------
arch/s390/oprofile/op_counter.h | 21 -
6 files changed, 1754 deletions(-)
Robert Richter
2016-06-14 13:28:23 UTC
Permalink
Raw Message
Post by Heiko Carstens
Post by Robert Richter
Heiko,
Post by Heiko Carstens
However I'm wondering if we shouldn't simply remove at least the s390
specific hwswampler code from the oprofile module. This would still leave
the common code timer based sampling mode for oprofile working on s390.
It looks like the oprofile user space utility nowadays (since 2012) uses
the kernel perf interface instead of the oprofile interface anyway, if
present. So the oprofile module itself doesn't seem to have too many users
left.
Any opinions?
yes, the kernel driver is not necessary for oprofile userland for a
while now. There is no ongoing development any longer, most patches
are due to changes in the kernel apis.
So if there is code that needs a larger rework due to other kernel
changes and there is no user anymore, I am fine with removing the code
instead of reworking it. I still would just keep existing code as long
as we can keep it unchanged (some like the lightwight of oprofile,
esp. in the embedded space). If there is a user of the code, a
Tested-by would be good for new code changes.
If there are users of the hwswampler, speak up now. Else, let's just
remove it.
Ok, so I'll wait a week or so and remove the code if nobody speaks up. Is
it ok for you if I add the patch to the s390 kernel tree?
Yes, pass it through your tree.
Post by Heiko Carstens
The patch would only remove s390 specific architecture code.
s390/oprofile: remove hardware sampler support
Remove hardware sampler support from oprofile module.
The oprofile user space utilty has been switched to use the kernel
perf interface, for which we also provide hardware sampling support.
In addition the hardware sampling support is also slightly broken: it
supports only 16 bits for the pid and therefore would generate wrong
results on machines which have a pid >64k.
Also the pt_regs structure which was passed to oprofile common code
cannot necessarily be used to generate sane backtraces, since the
task(s) in question may run while the samples are fed to oprofile.
So the result would be more or less random.
However given that the only user space tools switched to the perf
interface already four years ago the hardware sampler code seems to be
unused code, and therefore it should be reasonable to remove it.
The timer based oprofile support continues to work.
Documentation/kernel-parameters.txt | 2 -
arch/s390/oprofile/Makefile | 1 -
arch/s390/oprofile/hwsampler.c | 1178 --------------------------------
arch/s390/oprofile/hwsampler.h | 63 --
arch/s390/oprofile/init.c | 489 -------------
arch/s390/oprofile/op_counter.h | 21 -
6 files changed, 1754 deletions(-)
Could you send the patch for review anyway?

Thanks,

-Robert
Heiko Carstens
2016-06-14 15:56:09 UTC
Permalink
Raw Message
Post by Robert Richter
Post by Heiko Carstens
Documentation/kernel-parameters.txt | 2 -
arch/s390/oprofile/Makefile | 1 -
arch/s390/oprofile/hwsampler.c | 1178 --------------------------------
arch/s390/oprofile/hwsampler.h | 63 --
arch/s390/oprofile/init.c | 489 -------------
arch/s390/oprofile/op_counter.h | 21 -
6 files changed, 1754 deletions(-)
Could you send the patch for review anyway?
Yes, of course. I added it below, hope that's ok.
[I did not yet add your Ack]
Post by Robert Richter
From 74ab0aefe07573358cc6a0c462ddc62ccba4c0cf Mon Sep 17 00:00:00 2001
From: Heiko Carstens <***@de.ibm.com>
Date: Fri, 10 Jun 2016 10:40:06 +0200
Subject: [PATCH] s390/oprofile: remove hardware sampler support

Remove hardware sampler support from oprofile module.

The oprofile user space utilty has been switched to use the kernel
perf interface, for which we also provide hardware sampling support.

In addition the hardware sampling support is also slightly broken: it
supports only 16 bits for the pid and therefore would generate wrong
results on machines which have a pid >64k.

Also the pt_regs structure which was passed to oprofile common code
cannot necessarily be used to generate sane backtraces, since the
task(s) in question may run while the samples are fed to oprofile.
So the result would be more or less random.

However given that the only user space tools switched to the perf
interface already four years ago the hardware sampler code seems to be
unused code, and therefore it should be reasonable to remove it.

The timer based oprofile support continues to work.

Signed-off-by: Heiko Carstens <***@de.ibm.com>
---
Documentation/kernel-parameters.txt | 2 -
arch/s390/oprofile/Makefile | 1 -
arch/s390/oprofile/hwsampler.c | 1178 -----------------------------------
arch/s390/oprofile/hwsampler.h | 63 --
arch/s390/oprofile/init.c | 489 ---------------
arch/s390/oprofile/op_counter.h | 21 -
6 files changed, 1754 deletions(-)
delete mode 100644 arch/s390/oprofile/hwsampler.c
delete mode 100644 arch/s390/oprofile/hwsampler.h
delete mode 100644 arch/s390/oprofile/op_counter.h

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 82b42c958d1c..68b0c022861a 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2788,8 +2788,6 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
timer: [X86] Force use of architectural NMI
timer mode (see also oprofile.timer
for generic hr timer mode)
- [s390] Force legacy basic mode sampling
- (report cpu_type "timer")

oops=panic Always panic on oopses. Default is to just kill the
process, but there is a small probability of
diff --git a/arch/s390/oprofile/Makefile b/arch/s390/oprofile/Makefile
index 496e4a7ee00e..e9dd41b0b8d3 100644
--- a/arch/s390/oprofile/Makefile
+++ b/arch/s390/oprofile/Makefile
@@ -7,4 +7,3 @@ DRIVER_OBJS = $(addprefix ../../../drivers/oprofile/, \
timer_int.o )

oprofile-y := $(DRIVER_OBJS) init.o
-oprofile-y += hwsampler.o
diff --git a/arch/s390/oprofile/hwsampler.c b/arch/s390/oprofile/hwsampler.c
deleted file mode 100644
index ff9b4eb34589..000000000000
--- a/arch/s390/oprofile/hwsampler.c
+++ /dev/null
@@ -1,1178 +0,0 @@
-/*
- * Copyright IBM Corp. 2010
- * Author: Heinz Graalfs <***@de.ibm.com>
- */
-
-#include <linux/kernel_stat.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/smp.h>
-#include <linux/errno.h>
-#include <linux/workqueue.h>
-#include <linux/interrupt.h>
-#include <linux/notifier.h>
-#include <linux/cpu.h>
-#include <linux/semaphore.h>
-#include <linux/oom.h>
-#include <linux/oprofile.h>
-
-#include <asm/facility.h>
-#include <asm/cpu_mf.h>
-#include <asm/irq.h>
-
-#include "hwsampler.h"
-#include "op_counter.h"
-
-#define MAX_NUM_SDB 511
-#define MIN_NUM_SDB 1
-
-DECLARE_PER_CPU(struct hws_cpu_buffer, sampler_cpu_buffer);
-
-struct hws_execute_parms {
- void *buffer;
- signed int rc;
-};
-
-DEFINE_PER_CPU(struct hws_cpu_buffer, sampler_cpu_buffer);
-EXPORT_PER_CPU_SYMBOL(sampler_cpu_buffer);
-
-static DEFINE_MUTEX(hws_sem);
-static DEFINE_MUTEX(hws_sem_oom);
-
-static unsigned char hws_flush_all;
-static unsigned int hws_oom;
-static unsigned int hws_alert;
-static struct workqueue_struct *hws_wq;
-
-static unsigned int hws_state;
-enum {
- HWS_INIT = 1,
- HWS_DEALLOCATED,
- HWS_STOPPED,
- HWS_STARTED,
- HWS_STOPPING };
-
-/* set to 1 if called by kernel during memory allocation */
-static unsigned char oom_killer_was_active;
-/* size of SDBT and SDB as of allocate API */
-static unsigned long num_sdbt = 100;
-static unsigned long num_sdb = 511;
-/* sampling interval (machine cycles) */
-static unsigned long interval;
-
-static unsigned long min_sampler_rate;
-static unsigned long max_sampler_rate;
-
-static void execute_qsi(void *parms)
-{
- struct hws_execute_parms *ep = parms;
-
- ep->rc = qsi(ep->buffer);
-}
-
-static void execute_ssctl(void *parms)
-{
- struct hws_execute_parms *ep = parms;
-
- ep->rc = lsctl(ep->buffer);
-}
-
-static int smp_ctl_ssctl_stop(int cpu)
-{
- int rc;
- struct hws_execute_parms ep;
- struct hws_cpu_buffer *cb;
-
- cb = &per_cpu(sampler_cpu_buffer, cpu);
-
- cb->ssctl.es = 0;
- cb->ssctl.cs = 0;
-
- ep.buffer = &cb->ssctl;
- smp_call_function_single(cpu, execute_ssctl, &ep, 1);
- rc = ep.rc;
- if (rc) {
- printk(KERN_ERR "hwsampler: CPU %d CPUMF SSCTL failed.\n", cpu);
- dump_stack();
- }
-
- ep.buffer = &cb->qsi;
- smp_call_function_single(cpu, execute_qsi, &ep, 1);
-
- if (cb->qsi.es || cb->qsi.cs) {
- printk(KERN_EMERG "CPUMF sampling did not stop properly.\n");
- dump_stack();
- }
-
- return rc;
-}
-
-static int smp_ctl_ssctl_deactivate(int cpu)
-{
- int rc;
- struct hws_execute_parms ep;
- struct hws_cpu_buffer *cb;
-
- cb = &per_cpu(sampler_cpu_buffer, cpu);
-
- cb->ssctl.es = 1;
- cb->ssctl.cs = 0;
-
- ep.buffer = &cb->ssctl;
- smp_call_function_single(cpu, execute_ssctl, &ep, 1);
- rc = ep.rc;
- if (rc)
- printk(KERN_ERR "hwsampler: CPU %d CPUMF SSCTL failed.\n", cpu);
-
- ep.buffer = &cb->qsi;
- smp_call_function_single(cpu, execute_qsi, &ep, 1);
-
- if (cb->qsi.cs)
- printk(KERN_EMERG "CPUMF sampling was not set inactive.\n");
-
- return rc;
-}
-
-static int smp_ctl_ssctl_enable_activate(int cpu, unsigned long interval)
-{
- int rc;
- struct hws_execute_parms ep;
- struct hws_cpu_buffer *cb;
-
- cb = &per_cpu(sampler_cpu_buffer, cpu);
-
- cb->ssctl.h = 1;
- cb->ssctl.tear = cb->first_sdbt;
- cb->ssctl.dear = *(unsigned long *) cb->first_sdbt;
- cb->ssctl.interval = interval;
- cb->ssctl.es = 1;
- cb->ssctl.cs = 1;
-
- ep.buffer = &cb->ssctl;
- smp_call_function_single(cpu, execute_ssctl, &ep, 1);
- rc = ep.rc;
- if (rc)
- printk(KERN_ERR "hwsampler: CPU %d CPUMF SSCTL failed.\n", cpu);
-
- ep.buffer = &cb->qsi;
- smp_call_function_single(cpu, execute_qsi, &ep, 1);
- if (ep.rc)
- printk(KERN_ERR "hwsampler: CPU %d CPUMF QSI failed.\n", cpu);
-
- return rc;
-}
-
-static int smp_ctl_qsi(int cpu)
-{
- struct hws_execute_parms ep;
- struct hws_cpu_buffer *cb;
-
- cb = &per_cpu(sampler_cpu_buffer, cpu);
-
- ep.buffer = &cb->qsi;
- smp_call_function_single(cpu, execute_qsi, &ep, 1);
-
- return ep.rc;
-}
-
-static void hws_ext_handler(struct ext_code ext_code,
- unsigned int param32, unsigned long param64)
-{
- struct hws_cpu_buffer *cb = this_cpu_ptr(&sampler_cpu_buffer);
-
- if (!(param32 & CPU_MF_INT_SF_MASK))
- return;
-
- if (!hws_alert)
- return;
-
- inc_irq_stat(IRQEXT_CMS);
- atomic_xchg(&cb->ext_params, atomic_read(&cb->ext_params) | param32);
-
- if (hws_wq)
- queue_work(hws_wq, &cb->worker);
-}
-
-static void worker(struct work_struct *work);
-
-static void add_samples_to_oprofile(unsigned cpu, unsigned long *,
- unsigned long *dear);
-
-static void init_all_cpu_buffers(void)
-{
- int cpu;
- struct hws_cpu_buffer *cb;
-
- for_each_online_cpu(cpu) {
- cb = &per_cpu(sampler_cpu_buffer, cpu);
- memset(cb, 0, sizeof(struct hws_cpu_buffer));
- }
-}
-
-static void prepare_cpu_buffers(void)
-{
- struct hws_cpu_buffer *cb;
- int cpu;
-
- for_each_online_cpu(cpu) {
- cb = &per_cpu(sampler_cpu_buffer, cpu);
- atomic_set(&cb->ext_params, 0);
- cb->worker_entry = 0;
- cb->sample_overflow = 0;
- cb->req_alert = 0;
- cb->incorrect_sdbt_entry = 0;
- cb->invalid_entry_address = 0;
- cb->loss_of_sample_data = 0;
- cb->sample_auth_change_alert = 0;
- cb->finish = 0;
- cb->oom = 0;
- cb->stop_mode = 0;
- }
-}
-
-/*
- * allocate_sdbt() - allocate sampler memory
- * @cpu: the cpu for which sampler memory is allocated
- *
- * A 4K page is allocated for each requested SDBT.
- * A maximum of 511 4K pages are allocated for the SDBs in each of the SDBTs.
- * Set ALERT_REQ mask in each SDBs trailer.
- * Returns zero if successful, <0 otherwise.
- */
-static int allocate_sdbt(int cpu)
-{
- int j, k, rc;
- unsigned long *sdbt;
- unsigned long sdb;
- unsigned long *tail;
- unsigned long *trailer;
- struct hws_cpu_buffer *cb;
-
- cb = &per_cpu(sampler_cpu_buffer, cpu);
-
- if (cb->first_sdbt)
- return -EINVAL;
-
- sdbt = NULL;
- tail = sdbt;
-
- for (j = 0; j < num_sdbt; j++) {
- sdbt = (unsigned long *)get_zeroed_page(GFP_KERNEL);
-
- mutex_lock(&hws_sem_oom);
- /* OOM killer might have been activated */
- barrier();
- if (oom_killer_was_active || !sdbt) {
- if (sdbt)
- free_page((unsigned long)sdbt);
-
- goto allocate_sdbt_error;
- }
- if (cb->first_sdbt == 0)
- cb->first_sdbt = (unsigned long)sdbt;
-
- /* link current page to tail of chain */
- if (tail)
- *tail = (unsigned long)(void *)sdbt + 1;
-
- mutex_unlock(&hws_sem_oom);
-
- for (k = 0; k < num_sdb; k++) {
- /* get and set SDB page */
- sdb = get_zeroed_page(GFP_KERNEL);
-
- mutex_lock(&hws_sem_oom);
- /* OOM killer might have been activated */
- barrier();
- if (oom_killer_was_active || !sdb) {
- if (sdb)
- free_page(sdb);
-
- goto allocate_sdbt_error;
- }
- *sdbt = sdb;
- trailer = trailer_entry_ptr(*sdbt);
- *trailer = SDB_TE_ALERT_REQ_MASK;
- sdbt++;
- mutex_unlock(&hws_sem_oom);
- }
- tail = sdbt;
- }
- mutex_lock(&hws_sem_oom);
- if (oom_killer_was_active)
- goto allocate_sdbt_error;
-
- rc = 0;
- if (tail)
- *tail = (unsigned long)
- ((void *)cb->first_sdbt) + 1;
-
-allocate_sdbt_exit:
- mutex_unlock(&hws_sem_oom);
- return rc;
-
-allocate_sdbt_error:
- rc = -ENOMEM;
- goto allocate_sdbt_exit;
-}
-
-/*
- * deallocate_sdbt() - deallocate all sampler memory
- *
- * For each online CPU all SDBT trees are deallocated.
- * Returns the number of freed pages.
- */
-static int deallocate_sdbt(void)
-{
- int cpu;
- int counter;
-
- counter = 0;
-
- for_each_online_cpu(cpu) {
- unsigned long start;
- unsigned long sdbt;
- unsigned long *curr;
- struct hws_cpu_buffer *cb;
-
- cb = &per_cpu(sampler_cpu_buffer, cpu);
-
- if (!cb->first_sdbt)
- continue;
-
- sdbt = cb->first_sdbt;
- curr = (unsigned long *) sdbt;
- start = sdbt;
-
- /* we'll free the SDBT after all SDBs are processed... */
- while (1) {
- if (!*curr || !sdbt)
- break;
-
- /* watch for link entry reset if found */
- if (is_link_entry(curr)) {
- curr = get_next_sdbt(curr);
- if (sdbt)
- free_page(sdbt);
-
- /* we are done if we reach the start */
- if ((unsigned long) curr == start)
- break;
- else
- sdbt = (unsigned long) curr;
- } else {
- /* process SDB pointer */
- if (*curr) {
- free_page(*curr);
- curr++;
- }
- }
- counter++;
- }
- cb->first_sdbt = 0;
- }
- return counter;
-}
-
-static int start_sampling(int cpu)
-{
- int rc;
- struct hws_cpu_buffer *cb;
-
- cb = &per_cpu(sampler_cpu_buffer, cpu);
- rc = smp_ctl_ssctl_enable_activate(cpu, interval);
- if (rc) {
- printk(KERN_INFO "hwsampler: CPU %d ssctl failed.\n", cpu);
- goto start_exit;
- }
-
- rc = -EINVAL;
- if (!cb->qsi.es) {
- printk(KERN_INFO "hwsampler: CPU %d ssctl not enabled.\n", cpu);
- goto start_exit;
- }
-
- if (!cb->qsi.cs) {
- printk(KERN_INFO "hwsampler: CPU %d ssctl not active.\n", cpu);
- goto start_exit;
- }
-
- printk(KERN_INFO
- "hwsampler: CPU %d, CPUMF Sampling started, interval %lu.\n",
- cpu, interval);
-
- rc = 0;
-
-start_exit:
- return rc;
-}
-
-static int stop_sampling(int cpu)
-{
- unsigned long v;
- int rc;
- struct hws_cpu_buffer *cb;
-
- rc = smp_ctl_qsi(cpu);
- WARN_ON(rc);
-
- cb = &per_cpu(sampler_cpu_buffer, cpu);
- if (!rc && !cb->qsi.es)
- printk(KERN_INFO "hwsampler: CPU %d, already stopped.\n", cpu);
-
- rc = smp_ctl_ssctl_stop(cpu);
- if (rc) {
- printk(KERN_INFO "hwsampler: CPU %d, ssctl stop error %d.\n",
- cpu, rc);
- goto stop_exit;
- }
-
- printk(KERN_INFO "hwsampler: CPU %d, CPUMF Sampling stopped.\n", cpu);
-
-stop_exit:
- v = cb->req_alert;
- if (v)
- printk(KERN_ERR "hwsampler: CPU %d CPUMF Request alert,"
- " count=%lu.\n", cpu, v);
-
- v = cb->loss_of_sample_data;
- if (v)
- printk(KERN_ERR "hwsampler: CPU %d CPUMF Loss of sample data,"
- " count=%lu.\n", cpu, v);
-
- v = cb->invalid_entry_address;
- if (v)
- printk(KERN_ERR "hwsampler: CPU %d CPUMF Invalid entry address,"
- " count=%lu.\n", cpu, v);
-
- v = cb->incorrect_sdbt_entry;
- if (v)
- printk(KERN_ERR
- "hwsampler: CPU %d CPUMF Incorrect SDBT address,"
- " count=%lu.\n", cpu, v);
-
- v = cb->sample_auth_change_alert;
- if (v)
- printk(KERN_ERR
- "hwsampler: CPU %d CPUMF Sample authorization change,"
- " count=%lu.\n", cpu, v);
-
- return rc;
-}
-
-static int check_hardware_prerequisites(void)
-{
- if (!test_facility(68))
- return -EOPNOTSUPP;
- return 0;
-}
-/*
- * hws_oom_callback() - the OOM callback function
- *
- * In case the callback is invoked during memory allocation for the
- * hw sampler, all obtained memory is deallocated and a flag is set
- * so main sampler memory allocation can exit with a failure code.
- * In case the callback is invoked during sampling the hw sampler
- * is deactivated for all CPUs.
- */
-static int hws_oom_callback(struct notifier_block *nfb,
- unsigned long dummy, void *parm)
-{
- unsigned long *freed;
- int cpu;
- struct hws_cpu_buffer *cb;
-
- freed = parm;
-
- mutex_lock(&hws_sem_oom);
-
- if (hws_state == HWS_DEALLOCATED) {
- /* during memory allocation */
- if (oom_killer_was_active == 0) {
- oom_killer_was_active = 1;
- *freed += deallocate_sdbt();
- }
- } else {
- int i;
- cpu = get_cpu();
- cb = &per_cpu(sampler_cpu_buffer, cpu);
-
- if (!cb->oom) {
- for_each_online_cpu(i) {
- smp_ctl_ssctl_deactivate(i);
- cb->oom = 1;
- }
- cb->finish = 1;
-
- printk(KERN_INFO
- "hwsampler: CPU %d, OOM notify during CPUMF Sampling.\n",
- cpu);
- }
- }
-
- mutex_unlock(&hws_sem_oom);
-
- return NOTIFY_OK;
-}
-
-static struct notifier_block hws_oom_notifier = {
- .notifier_call = hws_oom_callback
-};
-
-static int hws_cpu_callback(struct notifier_block *nfb,
- unsigned long action, void *hcpu)
-{
- /* We do not have sampler space available for all possible CPUs.
- All CPUs should be online when hw sampling is activated. */
- return (hws_state <= HWS_DEALLOCATED) ? NOTIFY_OK : NOTIFY_BAD;
-}
-
-static struct notifier_block hws_cpu_notifier = {
- .notifier_call = hws_cpu_callback
-};
-
-/**
- * hwsampler_deactivate() - set hardware sampling temporarily inactive
- * @cpu: specifies the CPU to be set inactive.
- *
- * Returns 0 on success, !0 on failure.
- */
-int hwsampler_deactivate(unsigned int cpu)
-{
- /*
- * Deactivate hw sampling temporarily and flush the buffer
- * by pushing all the pending samples to oprofile buffer.
- *
- * This function can be called under one of the following conditions:
- * Memory unmap, task is exiting.
- */
- int rc;
- struct hws_cpu_buffer *cb;
-
- rc = 0;
- mutex_lock(&hws_sem);
-
- cb = &per_cpu(sampler_cpu_buffer, cpu);
- if (hws_state == HWS_STARTED) {
- rc = smp_ctl_qsi(cpu);
- WARN_ON(rc);
- if (cb->qsi.cs) {
- rc = smp_ctl_ssctl_deactivate(cpu);
- if (rc) {
- printk(KERN_INFO
- "hwsampler: CPU %d, CPUMF Deactivation failed.\n", cpu);
- cb->finish = 1;
- hws_state = HWS_STOPPING;
- } else {
- hws_flush_all = 1;
- /* Add work to queue to read pending samples.*/
- queue_work_on(cpu, hws_wq, &cb->worker);
- }
- }
- }
- mutex_unlock(&hws_sem);
-
- if (hws_wq)
- flush_workqueue(hws_wq);
-
- return rc;
-}
-
-/**
- * hwsampler_activate() - activate/resume hardware sampling which was deactivated
- * @cpu: specifies the CPU to be set active.
- *
- * Returns 0 on success, !0 on failure.
- */
-int hwsampler_activate(unsigned int cpu)
-{
- /*
- * Re-activate hw sampling. This should be called in pair with
- * hwsampler_deactivate().
- */
- int rc;
- struct hws_cpu_buffer *cb;
-
- rc = 0;
- mutex_lock(&hws_sem);
-
- cb = &per_cpu(sampler_cpu_buffer, cpu);
- if (hws_state == HWS_STARTED) {
- rc = smp_ctl_qsi(cpu);
- WARN_ON(rc);
- if (!cb->qsi.cs) {
- hws_flush_all = 0;
- rc = smp_ctl_ssctl_enable_activate(cpu, interval);
- if (rc) {
- printk(KERN_ERR
- "CPU %d, CPUMF activate sampling failed.\n",
- cpu);
- }
- }
- }
-
- mutex_unlock(&hws_sem);
-
- return rc;
-}
-
-static int check_qsi_on_setup(void)
-{
- int rc;
- unsigned int cpu;
- struct hws_cpu_buffer *cb;
-
- for_each_online_cpu(cpu) {
- cb = &per_cpu(sampler_cpu_buffer, cpu);
- rc = smp_ctl_qsi(cpu);
- WARN_ON(rc);
- if (rc)
- return -EOPNOTSUPP;
-
- if (!cb->qsi.as) {
- printk(KERN_INFO "hwsampler: CPUMF sampling is not authorized.\n");
- return -EINVAL;
- }
-
- if (cb->qsi.es) {
- printk(KERN_WARNING "hwsampler: CPUMF is still enabled.\n");
- rc = smp_ctl_ssctl_stop(cpu);
- if (rc)
- return -EINVAL;
-
- printk(KERN_INFO
- "CPU %d, CPUMF Sampling stopped now.\n", cpu);
- }
- }
- return 0;
-}
-
-static int check_qsi_on_start(void)
-{
- unsigned int cpu;
- int rc;
- struct hws_cpu_buffer *cb;
-
- for_each_online_cpu(cpu) {
- cb = &per_cpu(sampler_cpu_buffer, cpu);
- rc = smp_ctl_qsi(cpu);
- WARN_ON(rc);
-
- if (!cb->qsi.as)
- return -EINVAL;
-
- if (cb->qsi.es)
- return -EINVAL;
-
- if (cb->qsi.cs)
- return -EINVAL;
- }
- return 0;
-}
-
-static void worker_on_start(unsigned int cpu)
-{
- struct hws_cpu_buffer *cb;
-
- cb = &per_cpu(sampler_cpu_buffer, cpu);
- cb->worker_entry = cb->first_sdbt;
-}
-
-static int worker_check_error(unsigned int cpu, int ext_params)
-{
- int rc;
- unsigned long *sdbt;
- struct hws_cpu_buffer *cb;
-
- rc = 0;
- cb = &per_cpu(sampler_cpu_buffer, cpu);
- sdbt = (unsigned long *) cb->worker_entry;
-
- if (!sdbt || !*sdbt)
- return -EINVAL;
-
- if (ext_params & CPU_MF_INT_SF_PRA)
- cb->req_alert++;
-
- if (ext_params & CPU_MF_INT_SF_LSDA)
- cb->loss_of_sample_data++;
-
- if (ext_params & CPU_MF_INT_SF_IAE) {
- cb->invalid_entry_address++;
- rc = -EINVAL;
- }
-
- if (ext_params & CPU_MF_INT_SF_ISE) {
- cb->incorrect_sdbt_entry++;
- rc = -EINVAL;
- }
-
- if (ext_params & CPU_MF_INT_SF_SACA) {
- cb->sample_auth_change_alert++;
- rc = -EINVAL;
- }
-
- return rc;
-}
-
-static void worker_on_finish(unsigned int cpu)
-{
- int rc, i;
- struct hws_cpu_buffer *cb;
-
- cb = &per_cpu(sampler_cpu_buffer, cpu);
-
- if (cb->finish) {
- rc = smp_ctl_qsi(cpu);
- WARN_ON(rc);
- if (cb->qsi.es) {
- printk(KERN_INFO
- "hwsampler: CPU %d, CPUMF Stop/Deactivate sampling.\n",
- cpu);
- rc = smp_ctl_ssctl_stop(cpu);
- if (rc)
- printk(KERN_INFO
- "hwsampler: CPU %d, CPUMF Deactivation failed.\n",
- cpu);
-
- for_each_online_cpu(i) {
- if (i == cpu)
- continue;
- if (!cb->finish) {
- cb->finish = 1;
- queue_work_on(i, hws_wq,
- &cb->worker);
- }
- }
- }
- }
-}
-
-static void worker_on_interrupt(unsigned int cpu)
-{
- unsigned long *sdbt;
- unsigned char done;
- struct hws_cpu_buffer *cb;
-
- cb = &per_cpu(sampler_cpu_buffer, cpu);
-
- sdbt = (unsigned long *) cb->worker_entry;
-
- done = 0;
- /* do not proceed if stop was entered,
- * forget the buffers not yet processed */
- while (!done && !cb->stop_mode) {
- unsigned long *trailer;
- struct hws_trailer_entry *te;
- unsigned long *dear = 0;
-
- trailer = trailer_entry_ptr(*sdbt);
- /* leave loop if no more work to do */
- if (!(*trailer & SDB_TE_BUFFER_FULL_MASK)) {
- done = 1;
- if (!hws_flush_all)
- continue;
- }
-
- te = (struct hws_trailer_entry *)trailer;
- cb->sample_overflow += te->overflow;
-
- add_samples_to_oprofile(cpu, sdbt, dear);
-
- /* reset trailer */
- xchg((unsigned char *) te, 0x40);
-
- /* advance to next sdb slot in current sdbt */
- sdbt++;
- /* in case link bit is set use address w/o link bit */
- if (is_link_entry(sdbt))
- sdbt = get_next_sdbt(sdbt);
-
- cb->worker_entry = (unsigned long)sdbt;
- }
-}
-
-static void add_samples_to_oprofile(unsigned int cpu, unsigned long *sdbt,
- unsigned long *dear)
-{
- struct hws_basic_entry *sample_data_ptr;
- unsigned long *trailer;
-
- trailer = trailer_entry_ptr(*sdbt);
- if (dear) {
- if (dear > trailer)
- return;
- trailer = dear;
- }
-
- sample_data_ptr = (struct hws_basic_entry *)(*sdbt);
-
- while ((unsigned long *)sample_data_ptr < trailer) {
- struct pt_regs *regs = NULL;
- struct task_struct *tsk = NULL;
-
- /*
- * Check sampling mode, 1 indicates basic (=customer) sampling
- * mode.
- */
- if (sample_data_ptr->def != 1) {
- /* sample slot is not yet written */
- break;
- } else {
- /* make sure we don't use it twice,
- * the next time the sampler will set it again */
- sample_data_ptr->def = 0;
- }
-
- /* Get pt_regs. */
- if (sample_data_ptr->P == 1) {
- /* userspace sample */
- unsigned int pid = sample_data_ptr->prim_asn;
- if (!counter_config.user)
- goto skip_sample;
- rcu_read_lock();
- tsk = pid_task(find_vpid(pid), PIDTYPE_PID);
- if (tsk)
- regs = task_pt_regs(tsk);
- rcu_read_unlock();
- } else {
- /* kernelspace sample */
- if (!counter_config.kernel)
- goto skip_sample;
- regs = task_pt_regs(current);
- }
-
- mutex_lock(&hws_sem);
- oprofile_add_ext_hw_sample(sample_data_ptr->ia, regs, 0,
- !sample_data_ptr->P, tsk);
- mutex_unlock(&hws_sem);
- skip_sample:
- sample_data_ptr++;
- }
-}
-
-static void worker(struct work_struct *work)
-{
- unsigned int cpu;
- int ext_params;
- struct hws_cpu_buffer *cb;
-
- cb = container_of(work, struct hws_cpu_buffer, worker);
- cpu = smp_processor_id();
- ext_params = atomic_xchg(&cb->ext_params, 0);
-
- if (!cb->worker_entry)
- worker_on_start(cpu);
-
- if (worker_check_error(cpu, ext_params))
- return;
-
- if (!cb->finish)
- worker_on_interrupt(cpu);
-
- if (cb->finish)
- worker_on_finish(cpu);
-}
-
-/**
- * hwsampler_allocate() - allocate memory for the hardware sampler
- * @sdbt: number of SDBTs per online CPU (must be > 0)
- * @sdb: number of SDBs per SDBT (minimum 1, maximum 511)
- *
- * Returns 0 on success, !0 on failure.
- */
-int hwsampler_allocate(unsigned long sdbt, unsigned long sdb)
-{
- int cpu, rc;
- mutex_lock(&hws_sem);
-
- rc = -EINVAL;
- if (hws_state != HWS_DEALLOCATED)
- goto allocate_exit;
-
- if (sdbt < 1)
- goto allocate_exit;
-
- if (sdb > MAX_NUM_SDB || sdb < MIN_NUM_SDB)
- goto allocate_exit;
-
- num_sdbt = sdbt;
- num_sdb = sdb;
-
- oom_killer_was_active = 0;
- register_oom_notifier(&hws_oom_notifier);
-
- for_each_online_cpu(cpu) {
- if (allocate_sdbt(cpu)) {
- unregister_oom_notifier(&hws_oom_notifier);
- goto allocate_error;
- }
- }
- unregister_oom_notifier(&hws_oom_notifier);
- if (oom_killer_was_active)
- goto allocate_error;
-
- hws_state = HWS_STOPPED;
- rc = 0;
-
-allocate_exit:
- mutex_unlock(&hws_sem);
- return rc;
-
-allocate_error:
- rc = -ENOMEM;
- printk(KERN_ERR "hwsampler: CPUMF Memory allocation failed.\n");
- goto allocate_exit;
-}
-
-/**
- * hwsampler_deallocate() - deallocate hardware sampler memory
- *
- * Returns 0 on success, !0 on failure.
- */
-int hwsampler_deallocate(void)
-{
- int rc;
-
- mutex_lock(&hws_sem);
-
- rc = -EINVAL;
- if (hws_state != HWS_STOPPED)
- goto deallocate_exit;
-
- irq_subclass_unregister(IRQ_SUBCLASS_MEASUREMENT_ALERT);
- hws_alert = 0;
- deallocate_sdbt();
-
- hws_state = HWS_DEALLOCATED;
- rc = 0;
-
-deallocate_exit:
- mutex_unlock(&hws_sem);
-
- return rc;
-}
-
-unsigned long hwsampler_query_min_interval(void)
-{
- return min_sampler_rate;
-}
-
-unsigned long hwsampler_query_max_interval(void)
-{
- return max_sampler_rate;
-}
-
-unsigned long hwsampler_get_sample_overflow_count(unsigned int cpu)
-{
- struct hws_cpu_buffer *cb;
-
- cb = &per_cpu(sampler_cpu_buffer, cpu);
-
- return cb->sample_overflow;
-}
-
-int hwsampler_setup(void)
-{
- int rc;
- int cpu;
- struct hws_cpu_buffer *cb;
-
- mutex_lock(&hws_sem);
-
- rc = -EINVAL;
- if (hws_state)
- goto setup_exit;
-
- hws_state = HWS_INIT;
-
- init_all_cpu_buffers();
-
- rc = check_hardware_prerequisites();
- if (rc)
- goto setup_exit;
-
- rc = check_qsi_on_setup();
- if (rc)
- goto setup_exit;
-
- rc = -EINVAL;
- hws_wq = create_workqueue("hwsampler");
- if (!hws_wq)
- goto setup_exit;
-
- register_cpu_notifier(&hws_cpu_notifier);
-
- for_each_online_cpu(cpu) {
- cb = &per_cpu(sampler_cpu_buffer, cpu);
- INIT_WORK(&cb->worker, worker);
- rc = smp_ctl_qsi(cpu);
- WARN_ON(rc);
- if (min_sampler_rate != cb->qsi.min_sampl_rate) {
- if (min_sampler_rate) {
- printk(KERN_WARNING
- "hwsampler: different min sampler rate values.\n");
- if (min_sampler_rate < cb->qsi.min_sampl_rate)
- min_sampler_rate =
- cb->qsi.min_sampl_rate;
- } else
- min_sampler_rate = cb->qsi.min_sampl_rate;
- }
- if (max_sampler_rate != cb->qsi.max_sampl_rate) {
- if (max_sampler_rate) {
- printk(KERN_WARNING
- "hwsampler: different max sampler rate values.\n");
- if (max_sampler_rate > cb->qsi.max_sampl_rate)
- max_sampler_rate =
- cb->qsi.max_sampl_rate;
- } else
- max_sampler_rate = cb->qsi.max_sampl_rate;
- }
- }
- register_external_irq(EXT_IRQ_MEASURE_ALERT, hws_ext_handler);
-
- hws_state = HWS_DEALLOCATED;
- rc = 0;
-
-setup_exit:
- mutex_unlock(&hws_sem);
- return rc;
-}
-
-int hwsampler_shutdown(void)
-{
- int rc;
-
- mutex_lock(&hws_sem);
-
- rc = -EINVAL;
- if (hws_state == HWS_DEALLOCATED || hws_state == HWS_STOPPED) {
- mutex_unlock(&hws_sem);
-
- if (hws_wq)
- flush_workqueue(hws_wq);
-
- mutex_lock(&hws_sem);
-
- if (hws_state == HWS_STOPPED) {
- irq_subclass_unregister(IRQ_SUBCLASS_MEASUREMENT_ALERT);
- hws_alert = 0;
- deallocate_sdbt();
- }
- if (hws_wq) {
- destroy_workqueue(hws_wq);
- hws_wq = NULL;
- }
-
- unregister_external_irq(EXT_IRQ_MEASURE_ALERT, hws_ext_handler);
- hws_state = HWS_INIT;
- rc = 0;
- }
- mutex_unlock(&hws_sem);
-
- unregister_cpu_notifier(&hws_cpu_notifier);
-
- return rc;
-}
-
-/**
- * hwsampler_start_all() - start hardware sampling on all online CPUs
- * @rate: specifies the used interval when samples are taken
- *
- * Returns 0 on success, !0 on failure.
- */
-int hwsampler_start_all(unsigned long rate)
-{
- int rc, cpu;
-
- mutex_lock(&hws_sem);
-
- hws_oom = 0;
-
- rc = -EINVAL;
- if (hws_state != HWS_STOPPED)
- goto start_all_exit;
-
- interval = rate;
-
- /* fail if rate is not valid */
- if (interval < min_sampler_rate || interval > max_sampler_rate)
- goto start_all_exit;
-
- rc = check_qsi_on_start();
- if (rc)
- goto start_all_exit;
-
- prepare_cpu_buffers();
-
- for_each_online_cpu(cpu) {
- rc = start_sampling(cpu);
- if (rc)
- break;
- }
- if (rc) {
- for_each_online_cpu(cpu) {
- stop_sampling(cpu);
- }
- goto start_all_exit;
- }
- hws_state = HWS_STARTED;
- rc = 0;
-
-start_all_exit:
- mutex_unlock(&hws_sem);
-
- if (rc)
- return rc;
-
- register_oom_notifier(&hws_oom_notifier);
- hws_oom = 1;
- hws_flush_all = 0;
- /* now let them in, 1407 CPUMF external interrupts */
- hws_alert = 1;
- irq_subclass_register(IRQ_SUBCLASS_MEASUREMENT_ALERT);
-
- return 0;
-}
-
-/**
- * hwsampler_stop_all() - stop hardware sampling on all online CPUs
- *
- * Returns 0 on success, !0 on failure.
- */
-int hwsampler_stop_all(void)
-{
- int tmp_rc, rc, cpu;
- struct hws_cpu_buffer *cb;
-
- mutex_lock(&hws_sem);
-
- rc = 0;
- if (hws_state == HWS_INIT) {
- mutex_unlock(&hws_sem);
- return 0;
- }
- hws_state = HWS_STOPPING;
- mutex_unlock(&hws_sem);
-
- for_each_online_cpu(cpu) {
- cb = &per_cpu(sampler_cpu_buffer, cpu);
- cb->stop_mode = 1;
- tmp_rc = stop_sampling(cpu);
- if (tmp_rc)
- rc = tmp_rc;
- }
-
- if (hws_wq)
- flush_workqueue(hws_wq);
-
- mutex_lock(&hws_sem);
- if (hws_oom) {
- unregister_oom_notifier(&hws_oom_notifier);
- hws_oom = 0;
- }
- hws_state = HWS_STOPPED;
- mutex_unlock(&hws_sem);
-
- return rc;
-}
diff --git a/arch/s390/oprofile/hwsampler.h b/arch/s390/oprofile/hwsampler.h
deleted file mode 100644
index a483d06f2fa7..000000000000
--- a/arch/s390/oprofile/hwsampler.h
+++ /dev/null
@@ -1,63 +0,0 @@
-/*
- * CPUMF HW sampler functions and internal structures
- *
- * Copyright IBM Corp. 2010
- * Author(s): Heinz Graalfs <***@de.ibm.com>
- */
-
-#ifndef HWSAMPLER_H_
-#define HWSAMPLER_H_
-
-#include <linux/workqueue.h>
-#include <asm/cpu_mf.h>
-
-struct hws_ssctl_request_block /* SET SAMPLING CONTROLS req block */
-{ /* bytes 0 - 7 Bit(s) */
- unsigned int s:1; /* 0: maximum buffer indicator */
- unsigned int h:1; /* 1: part. level reserved for VM use*/
- unsigned long b2_53:52; /* 2-53: zeros */
- unsigned int es:1; /* 54: sampling enable control */
- unsigned int b55_61:7; /* 55-61: - zeros */
- unsigned int cs:1; /* 62: sampling activation control */
- unsigned int b63:1; /* 63: zero */
- unsigned long interval; /* 8-15: sampling interval */
- unsigned long tear; /* 16-23: TEAR contents */
- unsigned long dear; /* 24-31: DEAR contents */
- /* 32-63: */
- unsigned long rsvrd1; /* reserved */
- unsigned long rsvrd2; /* reserved */
- unsigned long rsvrd3; /* reserved */
- unsigned long rsvrd4; /* reserved */
-};
-
-struct hws_cpu_buffer {
- unsigned long first_sdbt; /* @ of 1st SDB-Table for this CP*/
- unsigned long worker_entry;
- unsigned long sample_overflow; /* taken from SDB ... */
- struct hws_qsi_info_block qsi;
- struct hws_ssctl_request_block ssctl;
- struct work_struct worker;
- atomic_t ext_params;
- unsigned long req_alert;
- unsigned long loss_of_sample_data;
- unsigned long invalid_entry_address;
- unsigned long incorrect_sdbt_entry;
- unsigned long sample_auth_change_alert;
- unsigned int finish:1;
- unsigned int oom:1;
- unsigned int stop_mode:1;
-};
-
-int hwsampler_setup(void);
-int hwsampler_shutdown(void);
-int hwsampler_allocate(unsigned long sdbt, unsigned long sdb);
-int hwsampler_deallocate(void);
-unsigned long hwsampler_query_min_interval(void);
-unsigned long hwsampler_query_max_interval(void);
-int hwsampler_start_all(unsigned long interval);
-int hwsampler_stop_all(void);
-int hwsampler_deactivate(unsigned int cpu);
-int hwsampler_activate(unsigned int cpu);
-unsigned long hwsampler_get_sample_overflow_count(unsigned int cpu);
-
-#endif /*HWSAMPLER_H_*/
diff --git a/arch/s390/oprofile/init.c b/arch/s390/oprofile/init.c
index 791935a65800..16f4c3960b87 100644
--- a/arch/s390/oprofile/init.c
+++ b/arch/s390/oprofile/init.c
@@ -10,488 +10,8 @@
*/

#include <linux/oprofile.h>
-#include <linux/perf_event.h>
#include <linux/init.h>
-#include <linux/errno.h>
-#include <linux/fs.h>
-#include <linux/module.h>
#include <asm/processor.h>
-#include <asm/perf_event.h>
-
-#include "../../../drivers/oprofile/oprof.h"
-
-#include "hwsampler.h"
-#include "op_counter.h"
-
-#define DEFAULT_INTERVAL 4127518
-
-#define DEFAULT_SDBT_BLOCKS 1
-#define DEFAULT_SDB_BLOCKS 511
-
-static unsigned long oprofile_hw_interval = DEFAULT_INTERVAL;
-static unsigned long oprofile_min_interval;
-static unsigned long oprofile_max_interval;
-
-static unsigned long oprofile_sdbt_blocks = DEFAULT_SDBT_BLOCKS;
-static unsigned long oprofile_sdb_blocks = DEFAULT_SDB_BLOCKS;
-
-static int hwsampler_enabled;
-static int hwsampler_running; /* start_mutex must be held to change */
-static int hwsampler_available;
-
-static struct oprofile_operations timer_ops;
-
-struct op_counter_config counter_config;
-
-enum __force_cpu_type {
- reserved = 0, /* do not force */
- timer,
-};
-static int force_cpu_type;
-
-static int set_cpu_type(const char *str, struct kernel_param *kp)
-{
- if (!strcmp(str, "timer")) {
- force_cpu_type = timer;
- printk(KERN_INFO "oprofile: forcing timer to be returned "
- "as cpu type\n");
- } else {
- force_cpu_type = 0;
- }
-
- return 0;
-}
-module_param_call(cpu_type, set_cpu_type, NULL, NULL, 0);
-MODULE_PARM_DESC(cpu_type, "Force legacy basic mode sampling"
- "(report cpu_type \"timer\"");
-
-static int __oprofile_hwsampler_start(void)
-{
- int retval;
-
- retval = hwsampler_allocate(oprofile_sdbt_blocks, oprofile_sdb_blocks);
- if (retval)
- return retval;
-
- retval = hwsampler_start_all(oprofile_hw_interval);
- if (retval)
- hwsampler_deallocate();
-
- return retval;
-}
-
-static int oprofile_hwsampler_start(void)
-{
- int retval;
-
- hwsampler_running = hwsampler_enabled;
-
- if (!hwsampler_running)
- return timer_ops.start();
-
- retval = perf_reserve_sampling();
- if (retval)
- return retval;
-
- retval = __oprofile_hwsampler_start();
- if (retval)
- perf_release_sampling();
-
- return retval;
-}
-
-static void oprofile_hwsampler_stop(void)
-{
- if (!hwsampler_running) {
- timer_ops.stop();
- return;
- }
-
- hwsampler_stop_all();
- hwsampler_deallocate();
- perf_release_sampling();
- return;
-}
-
-/*
- * File ops used for:
- * /dev/oprofile/0/enabled
- * /dev/oprofile/hwsampling/hwsampler (cpu_type = timer)
- */
-
-static ssize_t hwsampler_read(struct file *file, char __user *buf,
- size_t count, loff_t *offset)
-{
- return oprofilefs_ulong_to_user(hwsampler_enabled, buf, count, offset);
-}
-
-static ssize_t hwsampler_write(struct file *file, char const __user *buf,
- size_t count, loff_t *offset)
-{
- unsigned long val;
- int retval;
-
- if (*offset)
- return -EINVAL;
-
- retval = oprofilefs_ulong_from_user(&val, buf, count);
- if (retval <= 0)
- return retval;
-
- if (val != 0 && val != 1)
- return -EINVAL;
-
- if (oprofile_started)
- /*
- * save to do without locking as we set
- * hwsampler_running in start() when start_mutex is
- * held
- */
- return -EBUSY;
-
- hwsampler_enabled = val;
-
- return count;
-}
-
-static const struct file_operations hwsampler_fops = {
- .read = hwsampler_read,
- .write = hwsampler_write,
-};
-
-/*
- * File ops used for:
- * /dev/oprofile/0/count
- * /dev/oprofile/hwsampling/hw_interval (cpu_type = timer)
- *
- * Make sure that the value is within the hardware range.
- */
-
-static ssize_t hw_interval_read(struct file *file, char __user *buf,
- size_t count, loff_t *offset)
-{
- return oprofilefs_ulong_to_user(oprofile_hw_interval, buf,
- count, offset);
-}
-
-static ssize_t hw_interval_write(struct file *file, char const __user *buf,
- size_t count, loff_t *offset)
-{
- unsigned long val;
- int retval;
-
- if (*offset)
- return -EINVAL;
- retval = oprofilefs_ulong_from_user(&val, buf, count);
- if (retval <= 0)
- return retval;
- if (val < oprofile_min_interval)
- oprofile_hw_interval = oprofile_min_interval;
- else if (val > oprofile_max_interval)
- oprofile_hw_interval = oprofile_max_interval;
- else
- oprofile_hw_interval = val;
-
- return count;
-}
-
-static const struct file_operations hw_interval_fops = {
- .read = hw_interval_read,
- .write = hw_interval_write,
-};
-
-/*
- * File ops used for:
- * /dev/oprofile/0/event
- * Only a single event with number 0 is supported with this counter.
- *
- * /dev/oprofile/0/unit_mask
- * This is a dummy file needed by the user space tools.
- * No value other than 0 is accepted or returned.
- */
-
-static ssize_t hwsampler_zero_read(struct file *file, char __user *buf,
- size_t count, loff_t *offset)
-{
- return oprofilefs_ulong_to_user(0, buf, count, offset);
-}
-
-static ssize_t hwsampler_zero_write(struct file *file, char const __user *buf,
- size_t count, loff_t *offset)
-{
- unsigned long val;
- int retval;
-
- if (*offset)
- return -EINVAL;
-
- retval = oprofilefs_ulong_from_user(&val, buf, count);
- if (retval <= 0)
- return retval;
- if (val != 0)
- return -EINVAL;
- return count;
-}
-
-static const struct file_operations zero_fops = {
- .read = hwsampler_zero_read,
- .write = hwsampler_zero_write,
-};
-
-/* /dev/oprofile/0/kernel file ops. */
-
-static ssize_t hwsampler_kernel_read(struct file *file, char __user *buf,
- size_t count, loff_t *offset)
-{
- return oprofilefs_ulong_to_user(counter_config.kernel,
- buf, count, offset);
-}
-
-static ssize_t hwsampler_kernel_write(struct file *file, char const __user *buf,
- size_t count, loff_t *offset)
-{
- unsigned long val;
- int retval;
-
- if (*offset)
- return -EINVAL;
-
- retval = oprofilefs_ulong_from_user(&val, buf, count);
- if (retval <= 0)
- return retval;
-
- if (val != 0 && val != 1)
- return -EINVAL;
-
- counter_config.kernel = val;
-
- return count;
-}
-
-static const struct file_operations kernel_fops = {
- .read = hwsampler_kernel_read,
- .write = hwsampler_kernel_write,
-};
-
-/* /dev/oprofile/0/user file ops. */
-
-static ssize_t hwsampler_user_read(struct file *file, char __user *buf,
- size_t count, loff_t *offset)
-{
- return oprofilefs_ulong_to_user(counter_config.user,
- buf, count, offset);
-}
-
-static ssize_t hwsampler_user_write(struct file *file, char const __user *buf,
- size_t count, loff_t *offset)
-{
- unsigned long val;
- int retval;
-
- if (*offset)
- return -EINVAL;
-
- retval = oprofilefs_ulong_from_user(&val, buf, count);
- if (retval <= 0)
- return retval;
-
- if (val != 0 && val != 1)
- return -EINVAL;
-
- counter_config.user = val;
-
- return count;
-}
-
-static const struct file_operations user_fops = {
- .read = hwsampler_user_read,
- .write = hwsampler_user_write,
-};
-
-
-/*
- * File ops used for: /dev/oprofile/timer/enabled
- * The value always has to be the inverted value of hwsampler_enabled. So
- * no separate variable is created. That way we do not need locking.
- */
-
-static ssize_t timer_enabled_read(struct file *file, char __user *buf,
- size_t count, loff_t *offset)
-{
- return oprofilefs_ulong_to_user(!hwsampler_enabled, buf, count, offset);
-}
-
-static ssize_t timer_enabled_write(struct file *file, char const __user *buf,
- size_t count, loff_t *offset)
-{
- unsigned long val;
- int retval;
-
- if (*offset)
- return -EINVAL;
-
- retval = oprofilefs_ulong_from_user(&val, buf, count);
- if (retval <= 0)
- return retval;
-
- if (val != 0 && val != 1)
- return -EINVAL;
-
- /* Timer cannot be disabled without having hardware sampling. */
- if (val == 0 && !hwsampler_available)
- return -EINVAL;
-
- if (oprofile_started)
- /*
- * save to do without locking as we set
- * hwsampler_running in start() when start_mutex is
- * held
- */
- return -EBUSY;
-
- hwsampler_enabled = !val;
-
- return count;
-}
-
-static const struct file_operations timer_enabled_fops = {
- .read = timer_enabled_read,
- .write = timer_enabled_write,
-};
-
-
-static int oprofile_create_hwsampling_files(struct dentry *root)
-{
- struct dentry *dir;
-
- dir = oprofilefs_mkdir(root, "timer");
- if (!dir)
- return -EINVAL;
-
- oprofilefs_create_file(dir, "enabled", &timer_enabled_fops);
-
- if (!hwsampler_available)
- return 0;
-
- /* reinitialize default values */
- hwsampler_enabled = 1;
- counter_config.kernel = 1;
- counter_config.user = 1;
-
- if (!force_cpu_type) {
- /*
- * Create the counter file system. A single virtual
- * counter is created which can be used to
- * enable/disable hardware sampling dynamically from
- * user space. The user space will configure a single
- * counter with a single event. The value of 'event'
- * and 'unit_mask' are not evaluated by the kernel code
- * and can only be set to 0.
- */
-
- dir = oprofilefs_mkdir(root, "0");
- if (!dir)
- return -EINVAL;
-
- oprofilefs_create_file(dir, "enabled", &hwsampler_fops);
- oprofilefs_create_file(dir, "event", &zero_fops);
- oprofilefs_create_file(dir, "count", &hw_interval_fops);
- oprofilefs_create_file(dir, "unit_mask", &zero_fops);
- oprofilefs_create_file(dir, "kernel", &kernel_fops);
- oprofilefs_create_file(dir, "user", &user_fops);
- oprofilefs_create_ulong(dir, "hw_sdbt_blocks",
- &oprofile_sdbt_blocks);
-
- } else {
- /*
- * Hardware sampling can be used but the cpu_type is
- * forced to timer in order to deal with legacy user
- * space tools. The /dev/oprofile/hwsampling fs is
- * provided in that case.
- */
- dir = oprofilefs_mkdir(root, "hwsampling");
- if (!dir)
- return -EINVAL;
-
- oprofilefs_create_file(dir, "hwsampler",
- &hwsampler_fops);
- oprofilefs_create_file(dir, "hw_interval",
- &hw_interval_fops);
- oprofilefs_create_ro_ulong(dir, "hw_min_interval",
- &oprofile_min_interval);
- oprofilefs_create_ro_ulong(dir, "hw_max_interval",
- &oprofile_max_interval);
- oprofilefs_create_ulong(dir, "hw_sdbt_blocks",
- &oprofile_sdbt_blocks);
- }
- return 0;
-}
-
-static int oprofile_hwsampler_init(struct oprofile_operations *ops)
-{
- /*
- * Initialize the timer mode infrastructure as well in order
- * to be able to switch back dynamically. oprofile_timer_init
- * is not supposed to fail.
- */
- if (oprofile_timer_init(ops))
- BUG();
-
- memcpy(&timer_ops, ops, sizeof(timer_ops));
- ops->create_files = oprofile_create_hwsampling_files;
-
- /*
- * If the user space tools do not support newer cpu types,
- * the force_cpu_type module parameter
- * can be used to always return \"timer\" as cpu type.
- */
- if (force_cpu_type != timer) {
- struct cpuid id;
-
- get_cpu_id (&id);
-
- switch (id.machine) {
- case 0x2097: case 0x2098: ops->cpu_type = "s390/z10"; break;
- case 0x2817: case 0x2818: ops->cpu_type = "s390/z196"; break;
- case 0x2827: case 0x2828: ops->cpu_type = "s390/zEC12"; break;
- case 0x2964: case 0x2965: ops->cpu_type = "s390/z13"; break;
- default: return -ENODEV;
- }
- }
-
- if (hwsampler_setup())
- return -ENODEV;
-
- /*
- * Query the range for the sampling interval from the
- * hardware.
- */
- oprofile_min_interval = hwsampler_query_min_interval();
- if (oprofile_min_interval == 0)
- return -ENODEV;
- oprofile_max_interval = hwsampler_query_max_interval();
- if (oprofile_max_interval == 0)
- return -ENODEV;
-
- /* The initial value should be sane */
- if (oprofile_hw_interval < oprofile_min_interval)
- oprofile_hw_interval = oprofile_min_interval;
- if (oprofile_hw_interval > oprofile_max_interval)
- oprofile_hw_interval = oprofile_max_interval;
-
- printk(KERN_INFO "oprofile: System z hardware sampling "
- "facility found.\n");
-
- ops->start = oprofile_hwsampler_start;
- ops->stop = oprofile_hwsampler_stop;
-
- return 0;
-}
-
-static void oprofile_hwsampler_exit(void)
-{
- hwsampler_shutdown();
-}

static int __s390_backtrace(void *data, unsigned long address)
{
@@ -514,18 +34,9 @@ static void s390_backtrace(struct pt_regs *regs, unsigned int depth)
int __init oprofile_arch_init(struct oprofile_operations *ops)
{
ops->backtrace = s390_backtrace;
-
- /*
- * -ENODEV is not reported to the caller. The module itself
- * will use the timer mode sampling as fallback and this is
- * always available.
- */
- hwsampler_available = oprofile_hwsampler_init(ops) == 0;
-
return 0;
}

void oprofile_arch_exit(void)
{
- oprofile_hwsampler_exit();
}
diff --git a/arch/s390/oprofile/op_counter.h b/arch/s390/oprofile/op_counter.h
deleted file mode 100644
index 61b2531eef17..000000000000
--- a/arch/s390/oprofile/op_counter.h
+++ /dev/null
@@ -1,21 +0,0 @@
-/*
- * Copyright IBM Corp. 2011
- * Author(s): Andreas Krebbel (***@linux.vnet.ibm.com)
- *
- * @remark Copyright 2011 OProfile authors
- */
-
-#ifndef OP_COUNTER_H
-#define OP_COUNTER_H
-
-struct op_counter_config {
- /* `enabled' maps to the hwsampler_file variable. */
- /* `count' maps to the oprofile_hw_interval variable. */
- /* `event' and `unit_mask' are unused. */
- unsigned long kernel;
- unsigned long user;
-};
-
-extern struct op_counter_config counter_config;
-
-#endif /* OP_COUNTER_H */
--
2.6.6
Hendrik Brueckner
2016-06-17 09:08:21 UTC
Permalink
Raw Message
Post by Heiko Carstens
Post by Robert Richter
Post by Heiko Carstens
Documentation/kernel-parameters.txt | 2 -
arch/s390/oprofile/Makefile | 1 -
arch/s390/oprofile/hwsampler.c | 1178 --------------------------------
arch/s390/oprofile/hwsampler.h | 63 --
arch/s390/oprofile/init.c | 489 -------------
arch/s390/oprofile/op_counter.h | 21 -
6 files changed, 1754 deletions(-)
Could you send the patch for review anyway?
Yes, of course. I added it below, hope that's ok.
[I did not yet add your Ack]
From 74ab0aefe07573358cc6a0c462ddc62ccba4c0cf Mon Sep 17 00:00:00 2001
Date: Fri, 10 Jun 2016 10:40:06 +0200
Subject: [PATCH] s390/oprofile: remove hardware sampler support
Remove hardware sampler support from oprofile module.
The oprofile user space utilty has been switched to use the kernel
perf interface, for which we also provide hardware sampling support.
In addition the hardware sampling support is also slightly broken: it
supports only 16 bits for the pid and therefore would generate wrong
results on machines which have a pid >64k.
Also the pt_regs structure which was passed to oprofile common code
cannot necessarily be used to generate sane backtraces, since the
task(s) in question may run while the samples are fed to oprofile.
So the result would be more or less random.
However given that the only user space tools switched to the perf
interface already four years ago the hardware sampler code seems to be
unused code, and therefore it should be reasonable to remove it.
The timer based oprofile support continues to work.
---
Documentation/kernel-parameters.txt | 2 -
arch/s390/oprofile/Makefile | 1 -
arch/s390/oprofile/hwsampler.c | 1178 -----------------------------------
arch/s390/oprofile/hwsampler.h | 63 --
arch/s390/oprofile/init.c | 489 ---------------
arch/s390/oprofile/op_counter.h | 21 -
6 files changed, 1754 deletions(-)
delete mode 100644 arch/s390/oprofile/hwsampler.c
delete mode 100644 arch/s390/oprofile/hwsampler.h
delete mode 100644 arch/s390/oprofile/op_counter.h
Reviewed-by: Hendrik Brueckner <***@linux.vnet.ibm.com>

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