Re: [PATCH 3/3] tracing/mm: Don't trace mm_page_pcpu_drain on offline cpus
On Friday 08 May 2015 07:48 PM, Steven Rostedt wrote: > On Fri, 08 May 2015 10:07:15 +0530 > Shreyas B Prabhu wrote: > > >> Hi Steve, >> Do you have any other suggestions for this patchset or will you take >> them as is? > > I'm fine with them (add my Acked-by), but I don't usually pull in > changes for include/trace/events/*.h files. Those are usually maintained > by the creators of the files (subsystems they represent). > Oh I didn't know that. Let me resend the patches with your Acked-by, this time cc'ing people who have added/edited the events. Thanks, Shreyas -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 3/3] tracing/mm: Don't trace mm_page_pcpu_drain on offline cpus
On Fri, 08 May 2015 10:07:15 +0530 Shreyas B Prabhu wrote: > Hi Steve, > Do you have any other suggestions for this patchset or will you take > them as is? I'm fine with them (add my Acked-by), but I don't usually pull in changes for include/trace/events/*.h files. Those are usually maintained by the creators of the files (subsystems they represent). But I could pull them in if need be. -- Steve -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 3/3] tracing/mm: Don't trace mm_page_pcpu_drain on offline cpus
On Fri, 08 May 2015 10:07:15 +0530 Shreyas B Prabhu shre...@linux.vnet.ibm.com wrote: Hi Steve, Do you have any other suggestions for this patchset or will you take them as is? I'm fine with them (add my Acked-by), but I don't usually pull in changes for include/trace/events/*.h files. Those are usually maintained by the creators of the files (subsystems they represent). But I could pull them in if need be. -- Steve -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 3/3] tracing/mm: Don't trace mm_page_pcpu_drain on offline cpus
On Friday 08 May 2015 07:48 PM, Steven Rostedt wrote: On Fri, 08 May 2015 10:07:15 +0530 Shreyas B Prabhu shre...@linux.vnet.ibm.com wrote: Hi Steve, Do you have any other suggestions for this patchset or will you take them as is? I'm fine with them (add my Acked-by), but I don't usually pull in changes for include/trace/events/*.h files. Those are usually maintained by the creators of the files (subsystems they represent). Oh I didn't know that. Let me resend the patches with your Acked-by, this time cc'ing people who have added/edited the events. Thanks, Shreyas -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 3/3] tracing/mm: Don't trace mm_page_pcpu_drain on offline cpus
On Wednesday 29 April 2015 10:38 PM, Steven Rostedt wrote: > On Wed, 29 Apr 2015 21:28:38 +0530 > Shreyas B Prabhu wrote: > >> >> >> On Wednesday 29 April 2015 08:48 PM, Steven Rostedt wrote: >>> On Wed, 29 Apr 2015 20:19:28 +0530 >>> Shreyas B Prabhu wrote: >>> IIUC there is no existing macro which can both add a condition and override printk format, hence the fall back to TRACE_EVENT_CONDITION. >>> >>> Hmm, want me to send you a patch that changes that? >>> >> I am not sure if its worth the effort now. It doesn't look like any >> other trace point apart from the above use case will benefit from it. >> Only smbus_write and smbus_reply seem to come close. But even they need >> separate TP_fast_assign. > > It shouldn't be a problem to implement. But I'm currently cleaning up > those files, and any changes will cause nasty conflicts. > > Lets do this. Push the current changes as is, and when I get around to > adding a DEFINE_EVENT_PRINT_CONDITION(), we can modify that code to use > it. > Hi Steve, Do you have any other suggestions for this patchset or will you take them as is? Thanks, Shreyas -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 3/3] tracing/mm: Don't trace mm_page_pcpu_drain on offline cpus
On Wednesday 29 April 2015 10:38 PM, Steven Rostedt wrote: On Wed, 29 Apr 2015 21:28:38 +0530 Shreyas B Prabhu shre...@linux.vnet.ibm.com wrote: On Wednesday 29 April 2015 08:48 PM, Steven Rostedt wrote: On Wed, 29 Apr 2015 20:19:28 +0530 Shreyas B Prabhu shre...@linux.vnet.ibm.com wrote: IIUC there is no existing macro which can both add a condition and override printk format, hence the fall back to TRACE_EVENT_CONDITION. Hmm, want me to send you a patch that changes that? I am not sure if its worth the effort now. It doesn't look like any other trace point apart from the above use case will benefit from it. Only smbus_write and smbus_reply seem to come close. But even they need separate TP_fast_assign. It shouldn't be a problem to implement. But I'm currently cleaning up those files, and any changes will cause nasty conflicts. Lets do this. Push the current changes as is, and when I get around to adding a DEFINE_EVENT_PRINT_CONDITION(), we can modify that code to use it. Hi Steve, Do you have any other suggestions for this patchset or will you take them as is? Thanks, Shreyas -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 3/3] tracing/mm: Don't trace mm_page_pcpu_drain on offline cpus
On Thursday 30 April 2015 10:06 AM, Preeti Murthy wrote: > On Wed, Apr 29, 2015 at 10:49 PM, Shreyas B Prabhu > wrote: >> >> >> On Wednesday 29 April 2015 10:38 PM, Steven Rostedt wrote: I am not sure if its worth the effort now. It doesn't look like any other trace point apart from the above use case will benefit from it. Only smbus_write and smbus_reply seem to come close. But even they need separate TP_fast_assign. >>> >>> It shouldn't be a problem to implement. But I'm currently cleaning up >>> those files, and any changes will cause nasty conflicts. >>> >>> Lets do this. Push the current changes as is, and when I get around to >>> adding a DEFINE_EVENT_PRINT_CONDITION(), we can modify that code to use >>> it. >>> >> Okay, sure. > > Looks good then. > > Reviewed-by: Preeti U Murthy Thanks a lot! -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 3/3] tracing/mm: Don't trace mm_page_pcpu_drain on offline cpus
On Wed, Apr 29, 2015 at 10:49 PM, Shreyas B Prabhu wrote: > > > On Wednesday 29 April 2015 10:38 PM, Steven Rostedt wrote: >>> I am not sure if its worth the effort now. It doesn't look like any >>> other trace point apart from the above use case will benefit from it. >>> Only smbus_write and smbus_reply seem to come close. But even they need >>> separate TP_fast_assign. >> >> It shouldn't be a problem to implement. But I'm currently cleaning up >> those files, and any changes will cause nasty conflicts. >> >> Lets do this. Push the current changes as is, and when I get around to >> adding a DEFINE_EVENT_PRINT_CONDITION(), we can modify that code to use >> it. >> > Okay, sure. Looks good then. Reviewed-by: Preeti U Murthy > > Thanks, > Shreyas > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 3/3] tracing/mm: Don't trace mm_page_pcpu_drain on offline cpus
On Wednesday 29 April 2015 10:38 PM, Steven Rostedt wrote: >> I am not sure if its worth the effort now. It doesn't look like any >> other trace point apart from the above use case will benefit from it. >> Only smbus_write and smbus_reply seem to come close. But even they need >> separate TP_fast_assign. > > It shouldn't be a problem to implement. But I'm currently cleaning up > those files, and any changes will cause nasty conflicts. > > Lets do this. Push the current changes as is, and when I get around to > adding a DEFINE_EVENT_PRINT_CONDITION(), we can modify that code to use > it. > Okay, sure. Thanks, Shreyas -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 3/3] tracing/mm: Don't trace mm_page_pcpu_drain on offline cpus
On Wed, 29 Apr 2015 21:28:38 +0530 Shreyas B Prabhu wrote: > > > On Wednesday 29 April 2015 08:48 PM, Steven Rostedt wrote: > > On Wed, 29 Apr 2015 20:19:28 +0530 > > Shreyas B Prabhu wrote: > > > >> IIUC there is no existing macro which can both add a condition and > >> override printk format, hence the fall back to TRACE_EVENT_CONDITION. > > > > Hmm, want me to send you a patch that changes that? > > > I am not sure if its worth the effort now. It doesn't look like any > other trace point apart from the above use case will benefit from it. > Only smbus_write and smbus_reply seem to come close. But even they need > separate TP_fast_assign. It shouldn't be a problem to implement. But I'm currently cleaning up those files, and any changes will cause nasty conflicts. Lets do this. Push the current changes as is, and when I get around to adding a DEFINE_EVENT_PRINT_CONDITION(), we can modify that code to use it. -- Steve -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 3/3] tracing/mm: Don't trace mm_page_pcpu_drain on offline cpus
On Wednesday 29 April 2015 08:48 PM, Steven Rostedt wrote: > On Wed, 29 Apr 2015 20:19:28 +0530 > Shreyas B Prabhu wrote: > >> IIUC there is no existing macro which can both add a condition and >> override printk format, hence the fall back to TRACE_EVENT_CONDITION. > > Hmm, want me to send you a patch that changes that? > I am not sure if its worth the effort now. It doesn't look like any other trace point apart from the above use case will benefit from it. Only smbus_write and smbus_reply seem to come close. But even they need separate TP_fast_assign. Thanks, Shreyas -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 3/3] tracing/mm: Don't trace mm_page_pcpu_drain on offline cpus
On Wed, 29 Apr 2015 20:19:28 +0530 Shreyas B Prabhu wrote: > IIUC there is no existing macro which can both add a condition and > override printk format, hence the fall back to TRACE_EVENT_CONDITION. Hmm, want me to send you a patch that changes that? -- Steve -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 3/3] tracing/mm: Don't trace mm_page_pcpu_drain on offline cpus
>> -DEFINE_EVENT_PRINT(mm_page, mm_page_pcpu_drain, >> +TRACE_EVENT_CONDITION(mm_page_pcpu_drain, >> >> TP_PROTO(struct page *page, unsigned int order, int migratetype), >> >> TP_ARGS(page, order, migratetype), >> >> + TP_CONDITION(cpu_online(smp_processor_id())), >> + >> + TP_STRUCT__entry( >> + __field(unsigned long, pfn ) >> + __field(unsigned int, order ) >> + __field(int,migratetype ) >> + ), >> + >> + TP_fast_assign( >> + __entry->pfn= page ? page_to_pfn(page) : -1UL; >> + __entry->order = order; >> + __entry->migratetype= migratetype; >> + ), >> + > > What was the need to do the above changes besides adding TP_CONDITION ? > IIUC there is no existing macro which can both add a condition and override printk format, hence the fall back to TRACE_EVENT_CONDITION. Thanks, Shreyas -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 3/3] tracing/mm: Don't trace mm_page_pcpu_drain on offline cpus
Ccing Paul,
On Tue, Apr 28, 2015 at 9:21 PM, Shreyas B. Prabhu
wrote:
> Since tracepoints use RCU for protection, they must not be called on
> offline cpus. trace_mm_page_pcpu_drain can be called on an offline cpu
> in this scenario caught by LOCKDEP:
>
> ===
> [ INFO: suspicious RCU usage. ]
> 4.1.0-rc1+ #9 Not tainted
> ---
> include/trace/events/kmem.h:265 suspicious rcu_dereference_check() usage!
>
> other info that might help us debug this:
>
> RCU used illegally from offline CPU!
> rcu_scheduler_active = 1, debug_locks = 1
> 1 lock held by swapper/5/0:
> #0: (&(>lock)->rlock){..-...}, at: []
> .free_pcppages_bulk+0x70/0x920
>
> stack backtrace:
> CPU: 5 PID: 0 Comm: swapper/5 Not tainted 4.1.0-rc1+ #9
> Call Trace:
> [c01fed2e7720] [c09dee8c] .dump_stack+0x98/0xd4 (unreliable)
> [c01fed2e77a0] [c0128d88] .lockdep_rcu_suspicious+0x108/0x170
> [c01fed2e7830] [c020794c] .free_pcppages_bulk+0x60c/0x920
> [c01fed2e7980] [c0208188] .free_hot_cold_page+0x208/0x280
> [c01fed2e7a30] [c004d000] .destroy_context+0x90/0xd0
> [c01fed2e7ab0] [c00bd1d8] .__mmdrop+0x58/0x160
> [c01fed2e7b40] [c01068e0] .idle_task_exit+0xf0/0x100
> [c01fed2e7bc0] [c0066948] .pnv_smp_cpu_kill_self+0x58/0x2c0
> [c01fed2e7ca0] [c003ce34] .cpu_die+0x34/0x50
> [c01fed2e7d10] [c00176d0] .arch_cpu_idle_dead+0x20/0x40
> [c01fed2e7d80] [c011f9a8] .cpu_startup_entry+0x708/0x7a0
> [c01fed2e7ec0] [c003cb6c] .start_secondary+0x36c/0x3a0
> [c01fed2e7f90] [c0008b6c] start_secondary_prolog+0x10/0x14
>
> Fix this by converting mm_page_pcpu_drain trace point into
> TRACE_EVENT_CONDITION
> where condition is cpu_online(smp_processor_id())
>
> Signed-off-by: Shreyas B. Prabhu
> ---
> include/trace/events/kmem.h | 16 +++-
> 1 file changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/include/trace/events/kmem.h b/include/trace/events/kmem.h
> index 4abda92..6cd975f 100644
> --- a/include/trace/events/kmem.h
> +++ b/include/trace/events/kmem.h
> @@ -257,12 +257,26 @@ DEFINE_EVENT(mm_page, mm_page_alloc_zone_locked,
> TP_ARGS(page, order, migratetype)
> );
>
> -DEFINE_EVENT_PRINT(mm_page, mm_page_pcpu_drain,
> +TRACE_EVENT_CONDITION(mm_page_pcpu_drain,
>
> TP_PROTO(struct page *page, unsigned int order, int migratetype),
>
> TP_ARGS(page, order, migratetype),
>
> + TP_CONDITION(cpu_online(smp_processor_id())),
> +
> + TP_STRUCT__entry(
> + __field(unsigned long, pfn )
> + __field(unsigned int, order )
> + __field(int,migratetype )
> + ),
> +
> + TP_fast_assign(
> + __entry->pfn= page ? page_to_pfn(page) : -1UL;
> + __entry->order = order;
> + __entry->migratetype= migratetype;
> + ),
> +
What was the need to do the above changes besides adding TP_CONDITION ?
Regards
Preeti U Murthy
--
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More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 3/3] tracing/mm: Don't trace mm_page_pcpu_drain on offline cpus
Ccing Paul,
On Tue, Apr 28, 2015 at 9:21 PM, Shreyas B. Prabhu
shre...@linux.vnet.ibm.com wrote:
Since tracepoints use RCU for protection, they must not be called on
offline cpus. trace_mm_page_pcpu_drain can be called on an offline cpu
in this scenario caught by LOCKDEP:
===
[ INFO: suspicious RCU usage. ]
4.1.0-rc1+ #9 Not tainted
---
include/trace/events/kmem.h:265 suspicious rcu_dereference_check() usage!
other info that might help us debug this:
RCU used illegally from offline CPU!
rcu_scheduler_active = 1, debug_locks = 1
1 lock held by swapper/5/0:
#0: ((zone-lock)-rlock){..-...}, at: [c02073b0]
.free_pcppages_bulk+0x70/0x920
stack backtrace:
CPU: 5 PID: 0 Comm: swapper/5 Not tainted 4.1.0-rc1+ #9
Call Trace:
[c01fed2e7720] [c09dee8c] .dump_stack+0x98/0xd4 (unreliable)
[c01fed2e77a0] [c0128d88] .lockdep_rcu_suspicious+0x108/0x170
[c01fed2e7830] [c020794c] .free_pcppages_bulk+0x60c/0x920
[c01fed2e7980] [c0208188] .free_hot_cold_page+0x208/0x280
[c01fed2e7a30] [c004d000] .destroy_context+0x90/0xd0
[c01fed2e7ab0] [c00bd1d8] .__mmdrop+0x58/0x160
[c01fed2e7b40] [c01068e0] .idle_task_exit+0xf0/0x100
[c01fed2e7bc0] [c0066948] .pnv_smp_cpu_kill_self+0x58/0x2c0
[c01fed2e7ca0] [c003ce34] .cpu_die+0x34/0x50
[c01fed2e7d10] [c00176d0] .arch_cpu_idle_dead+0x20/0x40
[c01fed2e7d80] [c011f9a8] .cpu_startup_entry+0x708/0x7a0
[c01fed2e7ec0] [c003cb6c] .start_secondary+0x36c/0x3a0
[c01fed2e7f90] [c0008b6c] start_secondary_prolog+0x10/0x14
Fix this by converting mm_page_pcpu_drain trace point into
TRACE_EVENT_CONDITION
where condition is cpu_online(smp_processor_id())
Signed-off-by: Shreyas B. Prabhu shre...@linux.vnet.ibm.com
---
include/trace/events/kmem.h | 16 +++-
1 file changed, 15 insertions(+), 1 deletion(-)
diff --git a/include/trace/events/kmem.h b/include/trace/events/kmem.h
index 4abda92..6cd975f 100644
--- a/include/trace/events/kmem.h
+++ b/include/trace/events/kmem.h
@@ -257,12 +257,26 @@ DEFINE_EVENT(mm_page, mm_page_alloc_zone_locked,
TP_ARGS(page, order, migratetype)
);
-DEFINE_EVENT_PRINT(mm_page, mm_page_pcpu_drain,
+TRACE_EVENT_CONDITION(mm_page_pcpu_drain,
TP_PROTO(struct page *page, unsigned int order, int migratetype),
TP_ARGS(page, order, migratetype),
+ TP_CONDITION(cpu_online(smp_processor_id())),
+
+ TP_STRUCT__entry(
+ __field(unsigned long, pfn )
+ __field(unsigned int, order )
+ __field(int,migratetype )
+ ),
+
+ TP_fast_assign(
+ __entry-pfn= page ? page_to_pfn(page) : -1UL;
+ __entry-order = order;
+ __entry-migratetype= migratetype;
+ ),
+
What was the need to do the above changes besides adding TP_CONDITION ?
Regards
Preeti U Murthy
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 3/3] tracing/mm: Don't trace mm_page_pcpu_drain on offline cpus
On Wednesday 29 April 2015 08:48 PM, Steven Rostedt wrote: On Wed, 29 Apr 2015 20:19:28 +0530 Shreyas B Prabhu shre...@linux.vnet.ibm.com wrote: IIUC there is no existing macro which can both add a condition and override printk format, hence the fall back to TRACE_EVENT_CONDITION. Hmm, want me to send you a patch that changes that? I am not sure if its worth the effort now. It doesn't look like any other trace point apart from the above use case will benefit from it. Only smbus_write and smbus_reply seem to come close. But even they need separate TP_fast_assign. Thanks, Shreyas -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 3/3] tracing/mm: Don't trace mm_page_pcpu_drain on offline cpus
On Wed, 29 Apr 2015 21:28:38 +0530 Shreyas B Prabhu shre...@linux.vnet.ibm.com wrote: On Wednesday 29 April 2015 08:48 PM, Steven Rostedt wrote: On Wed, 29 Apr 2015 20:19:28 +0530 Shreyas B Prabhu shre...@linux.vnet.ibm.com wrote: IIUC there is no existing macro which can both add a condition and override printk format, hence the fall back to TRACE_EVENT_CONDITION. Hmm, want me to send you a patch that changes that? I am not sure if its worth the effort now. It doesn't look like any other trace point apart from the above use case will benefit from it. Only smbus_write and smbus_reply seem to come close. But even they need separate TP_fast_assign. It shouldn't be a problem to implement. But I'm currently cleaning up those files, and any changes will cause nasty conflicts. Lets do this. Push the current changes as is, and when I get around to adding a DEFINE_EVENT_PRINT_CONDITION(), we can modify that code to use it. -- Steve -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 3/3] tracing/mm: Don't trace mm_page_pcpu_drain on offline cpus
On Wednesday 29 April 2015 10:38 PM, Steven Rostedt wrote: I am not sure if its worth the effort now. It doesn't look like any other trace point apart from the above use case will benefit from it. Only smbus_write and smbus_reply seem to come close. But even they need separate TP_fast_assign. It shouldn't be a problem to implement. But I'm currently cleaning up those files, and any changes will cause nasty conflicts. Lets do this. Push the current changes as is, and when I get around to adding a DEFINE_EVENT_PRINT_CONDITION(), we can modify that code to use it. Okay, sure. Thanks, Shreyas -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 3/3] tracing/mm: Don't trace mm_page_pcpu_drain on offline cpus
-DEFINE_EVENT_PRINT(mm_page, mm_page_pcpu_drain, +TRACE_EVENT_CONDITION(mm_page_pcpu_drain, TP_PROTO(struct page *page, unsigned int order, int migratetype), TP_ARGS(page, order, migratetype), + TP_CONDITION(cpu_online(smp_processor_id())), + + TP_STRUCT__entry( + __field(unsigned long, pfn ) + __field(unsigned int, order ) + __field(int,migratetype ) + ), + + TP_fast_assign( + __entry-pfn= page ? page_to_pfn(page) : -1UL; + __entry-order = order; + __entry-migratetype= migratetype; + ), + What was the need to do the above changes besides adding TP_CONDITION ? IIUC there is no existing macro which can both add a condition and override printk format, hence the fall back to TRACE_EVENT_CONDITION. Thanks, Shreyas -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 3/3] tracing/mm: Don't trace mm_page_pcpu_drain on offline cpus
On Wed, 29 Apr 2015 20:19:28 +0530 Shreyas B Prabhu shre...@linux.vnet.ibm.com wrote: IIUC there is no existing macro which can both add a condition and override printk format, hence the fall back to TRACE_EVENT_CONDITION. Hmm, want me to send you a patch that changes that? -- Steve -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 3/3] tracing/mm: Don't trace mm_page_pcpu_drain on offline cpus
On Wed, Apr 29, 2015 at 10:49 PM, Shreyas B Prabhu shre...@linux.vnet.ibm.com wrote: On Wednesday 29 April 2015 10:38 PM, Steven Rostedt wrote: I am not sure if its worth the effort now. It doesn't look like any other trace point apart from the above use case will benefit from it. Only smbus_write and smbus_reply seem to come close. But even they need separate TP_fast_assign. It shouldn't be a problem to implement. But I'm currently cleaning up those files, and any changes will cause nasty conflicts. Lets do this. Push the current changes as is, and when I get around to adding a DEFINE_EVENT_PRINT_CONDITION(), we can modify that code to use it. Okay, sure. Looks good then. Reviewed-by: Preeti U Murthy pre...@linux.vnet.ibm.com Thanks, Shreyas -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 3/3] tracing/mm: Don't trace mm_page_pcpu_drain on offline cpus
On Thursday 30 April 2015 10:06 AM, Preeti Murthy wrote: On Wed, Apr 29, 2015 at 10:49 PM, Shreyas B Prabhu shre...@linux.vnet.ibm.com wrote: On Wednesday 29 April 2015 10:38 PM, Steven Rostedt wrote: I am not sure if its worth the effort now. It doesn't look like any other trace point apart from the above use case will benefit from it. Only smbus_write and smbus_reply seem to come close. But even they need separate TP_fast_assign. It shouldn't be a problem to implement. But I'm currently cleaning up those files, and any changes will cause nasty conflicts. Lets do this. Push the current changes as is, and when I get around to adding a DEFINE_EVENT_PRINT_CONDITION(), we can modify that code to use it. Okay, sure. Looks good then. Reviewed-by: Preeti U Murthy pre...@linux.vnet.ibm.com Thanks a lot! -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH 3/3] tracing/mm: Don't trace mm_page_pcpu_drain on offline cpus
Since tracepoints use RCU for protection, they must not be called on
offline cpus. trace_mm_page_pcpu_drain can be called on an offline cpu
in this scenario caught by LOCKDEP:
===
[ INFO: suspicious RCU usage. ]
4.1.0-rc1+ #9 Not tainted
---
include/trace/events/kmem.h:265 suspicious rcu_dereference_check() usage!
other info that might help us debug this:
RCU used illegally from offline CPU!
rcu_scheduler_active = 1, debug_locks = 1
1 lock held by swapper/5/0:
#0: (&(>lock)->rlock){..-...}, at: []
.free_pcppages_bulk+0x70/0x920
stack backtrace:
CPU: 5 PID: 0 Comm: swapper/5 Not tainted 4.1.0-rc1+ #9
Call Trace:
[c01fed2e7720] [c09dee8c] .dump_stack+0x98/0xd4 (unreliable)
[c01fed2e77a0] [c0128d88] .lockdep_rcu_suspicious+0x108/0x170
[c01fed2e7830] [c020794c] .free_pcppages_bulk+0x60c/0x920
[c01fed2e7980] [c0208188] .free_hot_cold_page+0x208/0x280
[c01fed2e7a30] [c004d000] .destroy_context+0x90/0xd0
[c01fed2e7ab0] [c00bd1d8] .__mmdrop+0x58/0x160
[c01fed2e7b40] [c01068e0] .idle_task_exit+0xf0/0x100
[c01fed2e7bc0] [c0066948] .pnv_smp_cpu_kill_self+0x58/0x2c0
[c01fed2e7ca0] [c003ce34] .cpu_die+0x34/0x50
[c01fed2e7d10] [c00176d0] .arch_cpu_idle_dead+0x20/0x40
[c01fed2e7d80] [c011f9a8] .cpu_startup_entry+0x708/0x7a0
[c01fed2e7ec0] [c003cb6c] .start_secondary+0x36c/0x3a0
[c01fed2e7f90] [c0008b6c] start_secondary_prolog+0x10/0x14
Fix this by converting mm_page_pcpu_drain trace point into TRACE_EVENT_CONDITION
where condition is cpu_online(smp_processor_id())
Signed-off-by: Shreyas B. Prabhu
---
include/trace/events/kmem.h | 16 +++-
1 file changed, 15 insertions(+), 1 deletion(-)
diff --git a/include/trace/events/kmem.h b/include/trace/events/kmem.h
index 4abda92..6cd975f 100644
--- a/include/trace/events/kmem.h
+++ b/include/trace/events/kmem.h
@@ -257,12 +257,26 @@ DEFINE_EVENT(mm_page, mm_page_alloc_zone_locked,
TP_ARGS(page, order, migratetype)
);
-DEFINE_EVENT_PRINT(mm_page, mm_page_pcpu_drain,
+TRACE_EVENT_CONDITION(mm_page_pcpu_drain,
TP_PROTO(struct page *page, unsigned int order, int migratetype),
TP_ARGS(page, order, migratetype),
+ TP_CONDITION(cpu_online(smp_processor_id())),
+
+ TP_STRUCT__entry(
+ __field(unsigned long, pfn )
+ __field(unsigned int, order )
+ __field(int,migratetype )
+ ),
+
+ TP_fast_assign(
+ __entry->pfn= page ? page_to_pfn(page) : -1UL;
+ __entry->order = order;
+ __entry->migratetype= migratetype;
+ ),
+
TP_printk("page=%p pfn=%lu order=%d migratetype=%d",
pfn_to_page(__entry->pfn), __entry->pfn,
__entry->order, __entry->migratetype)
--
1.9.3
--
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Please read the FAQ at http://www.tux.org/lkml/
[PATCH 3/3] tracing/mm: Don't trace mm_page_pcpu_drain on offline cpus
Since tracepoints use RCU for protection, they must not be called on
offline cpus. trace_mm_page_pcpu_drain can be called on an offline cpu
in this scenario caught by LOCKDEP:
===
[ INFO: suspicious RCU usage. ]
4.1.0-rc1+ #9 Not tainted
---
include/trace/events/kmem.h:265 suspicious rcu_dereference_check() usage!
other info that might help us debug this:
RCU used illegally from offline CPU!
rcu_scheduler_active = 1, debug_locks = 1
1 lock held by swapper/5/0:
#0: ((zone-lock)-rlock){..-...}, at: [c02073b0]
.free_pcppages_bulk+0x70/0x920
stack backtrace:
CPU: 5 PID: 0 Comm: swapper/5 Not tainted 4.1.0-rc1+ #9
Call Trace:
[c01fed2e7720] [c09dee8c] .dump_stack+0x98/0xd4 (unreliable)
[c01fed2e77a0] [c0128d88] .lockdep_rcu_suspicious+0x108/0x170
[c01fed2e7830] [c020794c] .free_pcppages_bulk+0x60c/0x920
[c01fed2e7980] [c0208188] .free_hot_cold_page+0x208/0x280
[c01fed2e7a30] [c004d000] .destroy_context+0x90/0xd0
[c01fed2e7ab0] [c00bd1d8] .__mmdrop+0x58/0x160
[c01fed2e7b40] [c01068e0] .idle_task_exit+0xf0/0x100
[c01fed2e7bc0] [c0066948] .pnv_smp_cpu_kill_self+0x58/0x2c0
[c01fed2e7ca0] [c003ce34] .cpu_die+0x34/0x50
[c01fed2e7d10] [c00176d0] .arch_cpu_idle_dead+0x20/0x40
[c01fed2e7d80] [c011f9a8] .cpu_startup_entry+0x708/0x7a0
[c01fed2e7ec0] [c003cb6c] .start_secondary+0x36c/0x3a0
[c01fed2e7f90] [c0008b6c] start_secondary_prolog+0x10/0x14
Fix this by converting mm_page_pcpu_drain trace point into TRACE_EVENT_CONDITION
where condition is cpu_online(smp_processor_id())
Signed-off-by: Shreyas B. Prabhu shre...@linux.vnet.ibm.com
---
include/trace/events/kmem.h | 16 +++-
1 file changed, 15 insertions(+), 1 deletion(-)
diff --git a/include/trace/events/kmem.h b/include/trace/events/kmem.h
index 4abda92..6cd975f 100644
--- a/include/trace/events/kmem.h
+++ b/include/trace/events/kmem.h
@@ -257,12 +257,26 @@ DEFINE_EVENT(mm_page, mm_page_alloc_zone_locked,
TP_ARGS(page, order, migratetype)
);
-DEFINE_EVENT_PRINT(mm_page, mm_page_pcpu_drain,
+TRACE_EVENT_CONDITION(mm_page_pcpu_drain,
TP_PROTO(struct page *page, unsigned int order, int migratetype),
TP_ARGS(page, order, migratetype),
+ TP_CONDITION(cpu_online(smp_processor_id())),
+
+ TP_STRUCT__entry(
+ __field(unsigned long, pfn )
+ __field(unsigned int, order )
+ __field(int,migratetype )
+ ),
+
+ TP_fast_assign(
+ __entry-pfn= page ? page_to_pfn(page) : -1UL;
+ __entry-order = order;
+ __entry-migratetype= migratetype;
+ ),
+
TP_printk(page=%p pfn=%lu order=%d migratetype=%d,
pfn_to_page(__entry-pfn), __entry-pfn,
__entry-order, __entry-migratetype)
--
1.9.3
--
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More majordomo info at http://vger.kernel.org/majordomo-info.html
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