Commit 83cd81a3 authored by KOSAKI Motohiro's avatar KOSAKI Motohiro Committed by Linus Torvalds
Browse files

vmscan: implement swap token trace 



This is useful for observing swap token activity.

example output:

             zsh-1845  [000]   598.962716: update_swap_token_priority:
mm=ffff88015eaf7700 old_prio=1 new_prio=0
          memtoy-1830  [001]   602.033900: update_swap_token_priority:
mm=ffff880037a45880 old_prio=947 new_prio=949
          memtoy-1830  [000]   602.041509: update_swap_token_priority:
mm=ffff880037a45880 old_prio=949 new_prio=951
          memtoy-1830  [000]   602.051959: update_swap_token_priority:
mm=ffff880037a45880 old_prio=951 new_prio=953
          memtoy-1830  [000]   602.052188: update_swap_token_priority:
mm=ffff880037a45880 old_prio=953 new_prio=955
          memtoy-1830  [001]   602.427184: put_swap_token:
token_mm=ffff880037a45880
             zsh-1789  [000]   602.427281: replace_swap_token:
old_token_mm=          (null) old_prio=0 new_token_mm=ffff88015eaf7018
new_prio=2
             zsh-1789  [001]   602.433456: update_swap_token_priority:
mm=ffff88015eaf7018 old_prio=2 new_prio=4
             zsh-1789  [000]   602.437613: update_swap_token_priority:
mm=ffff88015eaf7018 old_prio=4 new_prio=6
             zsh-1789  [000]   602.443924: update_swap_token_priority:
mm=ffff88015eaf7018 old_prio=6 new_prio=8
             zsh-1789  [000]   602.451873: update_swap_token_priority:
mm=ffff88015eaf7018 old_prio=8 new_prio=10
             zsh-1789  [001]   602.462639: update_swap_token_priority:
mm=ffff88015eaf7018 old_prio=10 new_prio=12

Signed-off-by: default avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: default avatarRik van <Riel&lt;riel@redhat.com>
Reviewed-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent a433658c

include/trace/events/vmscan.h

+77 −0
Original line number Diff line number Diff line
@@ -6,6 +6,8 @@ 


#include <linux/types.h>

#include <linux/tracepoint.h>

#include <linux/mm.h>

#include <linux/memcontrol.h>

#include "gfpflags.h"



#define RECLAIM_WB_ANON		0x0001u
@@ -310,6 +312,81 @@ TRACE_EVENT(mm_vmscan_lru_shrink_inactive, 
		show_reclaim_flags(__entry->reclaim_flags))

);



TRACE_EVENT(replace_swap_token,

	TP_PROTO(struct mm_struct *old_mm,

		 struct mm_struct *new_mm),



	TP_ARGS(old_mm, new_mm),



	TP_STRUCT__entry(

		__field(struct mm_struct*,	old_mm)

		__field(unsigned int,		old_prio)

		__field(struct mm_struct*,	new_mm)

		__field(unsigned int,		new_prio)

	),



	TP_fast_assign(

		__entry->old_mm   = old_mm;

		__entry->old_prio = old_mm ? old_mm->token_priority : 0;

		__entry->new_mm   = new_mm;

		__entry->new_prio = new_mm->token_priority;

	),



	TP_printk("old_token_mm=%p old_prio=%u new_token_mm=%p new_prio=%u",

		  __entry->old_mm, __entry->old_prio,

		  __entry->new_mm, __entry->new_prio)

);



DECLARE_EVENT_CLASS(put_swap_token_template,

	TP_PROTO(struct mm_struct *swap_token_mm),



	TP_ARGS(swap_token_mm),



	TP_STRUCT__entry(

		__field(struct mm_struct*, swap_token_mm)

	),



	TP_fast_assign(

		__entry->swap_token_mm = swap_token_mm;

	),



	TP_printk("token_mm=%p", __entry->swap_token_mm)

);



DEFINE_EVENT(put_swap_token_template, put_swap_token,

	TP_PROTO(struct mm_struct *swap_token_mm),

	TP_ARGS(swap_token_mm)

);



DEFINE_EVENT_CONDITION(put_swap_token_template, disable_swap_token,

	TP_PROTO(struct mm_struct *swap_token_mm),

	TP_ARGS(swap_token_mm),

	TP_CONDITION(swap_token_mm != NULL)

);



TRACE_EVENT_CONDITION(update_swap_token_priority,

	TP_PROTO(struct mm_struct *mm,

		 unsigned int old_prio),



	TP_ARGS(mm, old_prio),



	TP_CONDITION(mm->token_priority != old_prio),



	TP_STRUCT__entry(

		__field(struct mm_struct*, mm)

		__field(unsigned int, old_prio)

		__field(unsigned int, new_prio)

	),



	TP_fast_assign(

		__entry->mm = mm;

		__entry->old_prio = old_prio;

		__entry->new_prio = mm->token_priority;

	),



	TP_printk("mm=%p old_prio=%u new_prio=%u",

		  __entry->mm, __entry->old_prio, __entry->new_prio)

);



#endif /* _TRACE_VMSCAN_H */

mm/thrash.c

+10 −1
Original line number Diff line number Diff line
@@ -23,6 +23,8 @@ 
#include <linux/swap.h>

#include <linux/memcontrol.h>



#include <trace/events/vmscan.h>



static DEFINE_SPINLOCK(swap_token_lock);

struct mm_struct *swap_token_mm;

struct mem_cgroup *swap_token_memcg;
@@ -49,6 +51,7 @@ static struct mem_cgroup *swap_token_memcg_from_mm(struct mm_struct *mm) 
void grab_swap_token(struct mm_struct *mm)

{

	int current_interval;

	unsigned int old_prio = mm->token_priority;



	global_faults++;
@@ -63,7 +66,7 @@ void grab_swap_token(struct mm_struct *mm) 


	if (mm == swap_token_mm) {

		mm->token_priority += 2;

		goto out;

		goto update_priority;

	}



	if (current_interval < mm->last_interval)
@@ -77,6 +80,9 @@ void grab_swap_token(struct mm_struct *mm) 
	if (mm->token_priority > swap_token_mm->token_priority)

		goto replace_token;



update_priority:

	trace_update_swap_token_priority(mm, old_prio);



out:

	mm->faultstamp = global_faults;

	mm->last_interval = current_interval;
@@ -85,6 +91,7 @@ out: 


replace_token:

	mm->token_priority += 2;

	trace_replace_swap_token(swap_token_mm, mm);

	swap_token_mm = mm;

	swap_token_memcg = swap_token_memcg_from_mm(mm);

	goto out;
@@ -95,6 +102,7 @@ void __put_swap_token(struct mm_struct *mm) 
{

	spin_lock(&swap_token_lock);

	if (likely(mm == swap_token_mm)) {

		trace_put_swap_token(swap_token_mm);

		swap_token_mm = NULL;

		swap_token_memcg = NULL;

	}
@@ -118,6 +126,7 @@ void disable_swap_token(struct mem_cgroup *memcg) 
	if (match_memcg(memcg, swap_token_memcg)) {

		spin_lock(&swap_token_lock);

		if (match_memcg(memcg, swap_token_memcg)) {

			trace_disable_swap_token(swap_token_mm);

			swap_token_mm = NULL;

			swap_token_memcg = NULL;

		}

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