* [PATCH RESEND v3] perf/core: Fix installing cgroup event into cpu
@ 2018-01-31 8:35 linxiulei
2018-02-03 5:58 ` kbuild test robot
2018-02-03 6:52 ` kbuild test robot
0 siblings, 2 replies; 3+ messages in thread
From: linxiulei @ 2018-01-31 8:35 UTC (permalink / raw)
To: peterz, jolsa, mingo, acme, alexander.shishkin, linux-kernel,
tglx, eranian, torvalds, linux-perf-users, brendan.d.gregg
Cc: yang_oliver, jinli.zjl, leilei.lin
From: "leilei.lin" <leilei.lin@alibaba-inc.com>
Do not install cgroup event into the CPU context and schedule it
if the cgroup is not running on this CPU
While there is no task of cgroup running specified CPU, current
kernel still install cgroup event into CPU context that causes
another cgroup event can't be installed into this CPU.
This patch prevent scheduling events at __perf_install_in_context()
and installing events at list_update_cgroup_event() if cgroup isn't
running on specified CPU.
Signed-off-by: leilei.lin <leilei.lin@alibaba-inc.com>
---
v2: Set cpuctx->cgrp only if the same cgroup is running on this
CPU otherwise following events couldn't be activated immediately
v3: Enhance the comments and commit message
kernel/events/core.c | 49 ++++++++++++++++++++++++++++++++++++-------------
1 file changed, 36 insertions(+), 13 deletions(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 4df5b69..fb5b167 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -933,31 +933,41 @@ list_update_cgroup_event(struct perf_event *event,
{
struct perf_cpu_context *cpuctx;
struct list_head *cpuctx_entry;
+ struct perf_cgroup *cgrp;
if (!is_cgroup_event(event))
return;
- if (add && ctx->nr_cgroups++)
- return;
- else if (!add && --ctx->nr_cgroups)
- return;
/*
* Because cgroup events are always per-cpu events,
* this will always be called from the right CPU.
*/
cpuctx = __get_cpu_context(ctx);
- cpuctx_entry = &cpuctx->cgrp_cpuctx_entry;
- /* cpuctx->cgrp is NULL unless a cgroup event is active in this CPU .*/
- if (add) {
- struct perf_cgroup *cgrp = perf_cgroup_from_task(current, ctx);
+ cgrp = perf_cgroup_from_task(current, ctx);
- list_add(cpuctx_entry, this_cpu_ptr(&cgrp_cpuctx_list));
- if (cgroup_is_descendant(cgrp->css.cgroup, event->cgrp->css.cgroup))
+ /*
+ * if only the cgroup is running on this cpu,
+ * we put/remove this cgroup into cpu context.
+ * Or it would case mismatch in following cgroup
+ * events at event_filter_match()
+ */
+ if (cgroup_is_descendant(cgrp->css.cgroup, event->cgrp->css.cgroup)) {
+ if (add)
cpuctx->cgrp = cgrp;
- } else {
- list_del(cpuctx_entry);
- cpuctx->cgrp = NULL;
+ else
+ cpuctx->cgrp = NULL;
}
+
+ if (add && ctx->nr_cgroups++)
+ return;
+ else if (!add && --ctx->nr_cgroups)
+ return;
+
+ cpuctx_entry = &cpuctx->cgrp_cpuctx_entry;
+ if (add)
+ list_add(cpuctx_entry, this_cpu_ptr(&cgrp_cpuctx_list));
+ else
+ list_del(cpuctx_entry);
}
#else /* !CONFIG_CGROUP_PERF */
@@ -2284,6 +2294,7 @@ static int __perf_install_in_context(void *info)
struct perf_event_context *ctx = event->ctx;
struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
struct perf_event_context *task_ctx = cpuctx->task_ctx;
+ struct perf_cgroup *cgrp;
bool reprogram = true;
int ret = 0;
@@ -2311,6 +2322,18 @@ static int __perf_install_in_context(void *info)
raw_spin_lock(&task_ctx->lock);
}
+ if (is_cgroup_event(event)) {
+ /*
+ * Only care about cgroup events.
+ *
+ * If only the task belongs to cgroup of this event,
+ * we will continue the installment
+ */
+ cgrp = perf_cgroup_from_task(current, ctx);
+ reprogram = cgroup_is_descendant(cgrp->css.cgroup,
+ event->cgrp->css.cgroup);
+ }
+
if (reprogram) {
ctx_sched_out(ctx, cpuctx, EVENT_TIME);
add_event_to_ctx(event, ctx);
--
2.8.4.31.g9ed660f
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH RESEND v3] perf/core: Fix installing cgroup event into cpu
2018-01-31 8:35 [PATCH RESEND v3] perf/core: Fix installing cgroup event into cpu linxiulei
@ 2018-02-03 5:58 ` kbuild test robot
2018-02-03 6:52 ` kbuild test robot
1 sibling, 0 replies; 3+ messages in thread
From: kbuild test robot @ 2018-02-03 5:58 UTC (permalink / raw)
To: linxiulei
Cc: kbuild-all, peterz, jolsa, mingo, acme, alexander.shishkin,
linux-kernel, tglx, eranian, torvalds, linux-perf-users,
brendan.d.gregg, yang_oliver, jinli.zjl, leilei.lin
[-- Attachment #1: Type: text/plain, Size: 3876 bytes --]
Hi leilei.lin,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on tip/perf/core]
[also build test ERROR on v4.15 next-20180202]
[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/linxiulei-gmail-com/perf-core-Fix-installing-cgroup-event-into-cpu/20180203-133110
config: i386-randconfig-x071-201804 (attached as .config)
compiler: gcc-7 (Debian 7.2.0-12) 7.2.1 20171025
reproduce:
# save the attached .config to linux build tree
make ARCH=i386
All errors (new ones prefixed by >>):
kernel/events/core.c: In function '__perf_install_in_context':
>> kernel/events/core.c:2332:10: error: implicit declaration of function 'perf_cgroup_from_task'; did you mean 'perf_cgroup_match'? [-Werror=implicit-function-declaration]
cgrp = perf_cgroup_from_task(current, ctx);
^~~~~~~~~~~~~~~~~~~~~
perf_cgroup_match
kernel/events/core.c:2332:8: warning: assignment makes pointer from integer without a cast [-Wint-conversion]
cgrp = perf_cgroup_from_task(current, ctx);
^
>> kernel/events/core.c:2333:40: error: dereferencing pointer to incomplete type 'struct perf_cgroup'
reprogram = cgroup_is_descendant(cgrp->css.cgroup,
^~
>> kernel/events/core.c:2334:11: error: 'struct perf_event' has no member named 'cgrp'
event->cgrp->css.cgroup);
^~
cc1: some warnings being treated as errors
vim +2332 kernel/events/core.c
2284
2285 /*
2286 * Cross CPU call to install and enable a performance event
2287 *
2288 * Very similar to remote_function() + event_function() but cannot assume that
2289 * things like ctx->is_active and cpuctx->task_ctx are set.
2290 */
2291 static int __perf_install_in_context(void *info)
2292 {
2293 struct perf_event *event = info;
2294 struct perf_event_context *ctx = event->ctx;
2295 struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
2296 struct perf_event_context *task_ctx = cpuctx->task_ctx;
2297 struct perf_cgroup *cgrp;
2298 bool reprogram = true;
2299 int ret = 0;
2300
2301 raw_spin_lock(&cpuctx->ctx.lock);
2302 if (ctx->task) {
2303 raw_spin_lock(&ctx->lock);
2304 task_ctx = ctx;
2305
2306 reprogram = (ctx->task == current);
2307
2308 /*
2309 * If the task is running, it must be running on this CPU,
2310 * otherwise we cannot reprogram things.
2311 *
2312 * If its not running, we don't care, ctx->lock will
2313 * serialize against it becoming runnable.
2314 */
2315 if (task_curr(ctx->task) && !reprogram) {
2316 ret = -ESRCH;
2317 goto unlock;
2318 }
2319
2320 WARN_ON_ONCE(reprogram && cpuctx->task_ctx && cpuctx->task_ctx != ctx);
2321 } else if (task_ctx) {
2322 raw_spin_lock(&task_ctx->lock);
2323 }
2324
2325 if (is_cgroup_event(event)) {
2326 /*
2327 * Only care about cgroup events.
2328 *
2329 * If only the task belongs to cgroup of this event,
2330 * we will continue the installment
2331 */
> 2332 cgrp = perf_cgroup_from_task(current, ctx);
> 2333 reprogram = cgroup_is_descendant(cgrp->css.cgroup,
> 2334 event->cgrp->css.cgroup);
2335 }
2336
2337 if (reprogram) {
2338 ctx_sched_out(ctx, cpuctx, EVENT_TIME);
2339 add_event_to_ctx(event, ctx);
2340 ctx_resched(cpuctx, task_ctx, get_event_type(event));
2341 } else {
2342 add_event_to_ctx(event, ctx);
2343 }
2344
2345 unlock:
2346 perf_ctx_unlock(cpuctx, task_ctx);
2347
2348 return ret;
2349 }
2350
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
[-- Attachment #2: .config.gz --]
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^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH RESEND v3] perf/core: Fix installing cgroup event into cpu
2018-01-31 8:35 [PATCH RESEND v3] perf/core: Fix installing cgroup event into cpu linxiulei
2018-02-03 5:58 ` kbuild test robot
@ 2018-02-03 6:52 ` kbuild test robot
1 sibling, 0 replies; 3+ messages in thread
From: kbuild test robot @ 2018-02-03 6:52 UTC (permalink / raw)
To: linxiulei
Cc: kbuild-all, peterz, jolsa, mingo, acme, alexander.shishkin,
linux-kernel, tglx, eranian, torvalds, linux-perf-users,
brendan.d.gregg, yang_oliver, jinli.zjl, leilei.lin
[-- Attachment #1: Type: text/plain, Size: 3831 bytes --]
Hi leilei.lin,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on tip/perf/core]
[also build test ERROR on v4.15 next-20180202]
[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/linxiulei-gmail-com/perf-core-Fix-installing-cgroup-event-into-cpu/20180203-133110
config: i386-randconfig-s0-201804 (attached as .config)
compiler: gcc-6 (Debian 6.4.0-9) 6.4.0 20171026
reproduce:
# save the attached .config to linux build tree
make ARCH=i386
All errors (new ones prefixed by >>):
kernel/events/core.c: In function '__perf_install_in_context':
>> kernel/events/core.c:2332:10: error: implicit declaration of function 'perf_cgroup_from_task' [-Werror=implicit-function-declaration]
cgrp = perf_cgroup_from_task(current, ctx);
^~~~~~~~~~~~~~~~~~~~~
kernel/events/core.c:2332:8: warning: assignment makes pointer from integer without a cast [-Wint-conversion]
cgrp = perf_cgroup_from_task(current, ctx);
^
kernel/events/core.c:2333:40: error: dereferencing pointer to incomplete type 'struct perf_cgroup'
reprogram = cgroup_is_descendant(cgrp->css.cgroup,
^~
kernel/events/core.c:2334:11: error: 'struct perf_event' has no member named 'cgrp'
event->cgrp->css.cgroup);
^~
cc1: some warnings being treated as errors
vim +/perf_cgroup_from_task +2332 kernel/events/core.c
2284
2285 /*
2286 * Cross CPU call to install and enable a performance event
2287 *
2288 * Very similar to remote_function() + event_function() but cannot assume that
2289 * things like ctx->is_active and cpuctx->task_ctx are set.
2290 */
2291 static int __perf_install_in_context(void *info)
2292 {
2293 struct perf_event *event = info;
2294 struct perf_event_context *ctx = event->ctx;
2295 struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
2296 struct perf_event_context *task_ctx = cpuctx->task_ctx;
2297 struct perf_cgroup *cgrp;
2298 bool reprogram = true;
2299 int ret = 0;
2300
2301 raw_spin_lock(&cpuctx->ctx.lock);
2302 if (ctx->task) {
2303 raw_spin_lock(&ctx->lock);
2304 task_ctx = ctx;
2305
2306 reprogram = (ctx->task == current);
2307
2308 /*
2309 * If the task is running, it must be running on this CPU,
2310 * otherwise we cannot reprogram things.
2311 *
2312 * If its not running, we don't care, ctx->lock will
2313 * serialize against it becoming runnable.
2314 */
2315 if (task_curr(ctx->task) && !reprogram) {
2316 ret = -ESRCH;
2317 goto unlock;
2318 }
2319
2320 WARN_ON_ONCE(reprogram && cpuctx->task_ctx && cpuctx->task_ctx != ctx);
2321 } else if (task_ctx) {
2322 raw_spin_lock(&task_ctx->lock);
2323 }
2324
2325 if (is_cgroup_event(event)) {
2326 /*
2327 * Only care about cgroup events.
2328 *
2329 * If only the task belongs to cgroup of this event,
2330 * we will continue the installment
2331 */
> 2332 cgrp = perf_cgroup_from_task(current, ctx);
2333 reprogram = cgroup_is_descendant(cgrp->css.cgroup,
2334 event->cgrp->css.cgroup);
2335 }
2336
2337 if (reprogram) {
2338 ctx_sched_out(ctx, cpuctx, EVENT_TIME);
2339 add_event_to_ctx(event, ctx);
2340 ctx_resched(cpuctx, task_ctx, get_event_type(event));
2341 } else {
2342 add_event_to_ctx(event, ctx);
2343 }
2344
2345 unlock:
2346 perf_ctx_unlock(cpuctx, task_ctx);
2347
2348 return ret;
2349 }
2350
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
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2018-01-31 8:35 [PATCH RESEND v3] perf/core: Fix installing cgroup event into cpu linxiulei
2018-02-03 5:58 ` kbuild test robot
2018-02-03 6:52 ` kbuild test robot
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