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authorKeika Kobayashi <kobayashi.kk@ncos.nec.co.jp>2008-07-25 04:48:52 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2008-07-25 13:53:47 -0400
commit873b47717732c2f33a4b14de02571a4295a02f0c (patch)
treeaaef0fe872dbd4ce5c290f3509e5db69f9a3f04a /include
parent3e85ba034deec351f02cb55ff225bbd616463841 (diff)
per-task-delay-accounting: add memory reclaim delay
Sometimes, application responses become bad under heavy memory load. Applications take a bit time to reclaim memory. The statistics, how long memory reclaim takes, will be useful to measure memory usage. This patch adds accounting memory reclaim to per-task-delay-accounting for accounting the time of do_try_to_free_pages(). <i.e> - When System is under low memory load, memory reclaim may not occur. $ free total used free shared buffers cached Mem: 8197800 1577300 6620500 0 4808 1516724 -/+ buffers/cache: 55768 8142032 Swap: 16386292 0 16386292 $ vmstat 1 procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu---- r b swpd free buff cache si so bi bo in cs us sy id wa 0 0 0 5069748 10612 3014060 0 0 0 0 3 26 0 0 100 0 0 0 0 5069748 10612 3014060 0 0 0 0 4 22 0 0 100 0 0 0 0 5069748 10612 3014060 0 0 0 0 3 18 0 0 100 0 Measure the time of tar command. $ ls -s test.dat 1501472 test.dat $ time tar cvf test.tar test.dat real 0m13.388s user 0m0.116s sys 0m5.304s $ ./delayget -d -p <pid> CPU count real total virtual total delay total 428 5528345500 5477116080 62749891 IO count delay total 338 8078977189 SWAP count delay total 0 0 RECLAIM count delay total 0 0 - When system is under heavy memory load memory reclaim may occur. $ vmstat 1 procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu---- r b swpd free buff cache si so bi bo in cs us sy id wa 0 0 7159032 49724 1812 3012 0 0 0 0 3 24 0 0 100 0 0 0 7159032 49724 1812 3012 0 0 0 0 4 24 0 0 100 0 0 0 7159032 49848 1812 3012 0 0 0 0 3 22 0 0 100 0 In this case, one process uses more 8G memory by execution of malloc() and memset(). $ time tar cvf test.tar test.dat real 1m38.563s <- increased by 85 sec user 0m0.140s sys 0m7.060s $ ./delayget -d -p <pid> CPU count real total virtual total delay total 9021 7140446250 7315277975 923201824 IO count delay total 8965 90466349669 SWAP count delay total 3 21036367 RECLAIM count delay total 740 61011951153 In the later case, the value of RECLAIM is increasing. So, taskstats can show how much memory reclaim influences TAT. Signed-off-by: Keika Kobayashi <kobayashi.kk@ncos.nec.co.jp> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujistu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
-rw-r--r--include/linux/delayacct.h19
-rw-r--r--include/linux/sched.h4
2 files changed, 23 insertions, 0 deletions
diff --git a/include/linux/delayacct.h b/include/linux/delayacct.h
index ab94bc083558..f352f06fa063 100644
--- a/include/linux/delayacct.h
+++ b/include/linux/delayacct.h
@@ -39,6 +39,8 @@ extern void __delayacct_blkio_start(void);
39extern void __delayacct_blkio_end(void); 39extern void __delayacct_blkio_end(void);
40extern int __delayacct_add_tsk(struct taskstats *, struct task_struct *); 40extern int __delayacct_add_tsk(struct taskstats *, struct task_struct *);
41extern __u64 __delayacct_blkio_ticks(struct task_struct *); 41extern __u64 __delayacct_blkio_ticks(struct task_struct *);
42extern void __delayacct_freepages_start(void);
43extern void __delayacct_freepages_end(void);
42 44
43static inline int delayacct_is_task_waiting_on_io(struct task_struct *p) 45static inline int delayacct_is_task_waiting_on_io(struct task_struct *p)
44{ 46{
@@ -107,6 +109,18 @@ static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk)
107 return 0; 109 return 0;
108} 110}
109 111
112static inline void delayacct_freepages_start(void)
113{
114 if (current->delays)
115 __delayacct_freepages_start();
116}
117
118static inline void delayacct_freepages_end(void)
119{
120 if (current->delays)
121 __delayacct_freepages_end();
122}
123
110#else 124#else
111static inline void delayacct_set_flag(int flag) 125static inline void delayacct_set_flag(int flag)
112{} 126{}
@@ -129,6 +143,11 @@ static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk)
129{ return 0; } 143{ return 0; }
130static inline int delayacct_is_task_waiting_on_io(struct task_struct *p) 144static inline int delayacct_is_task_waiting_on_io(struct task_struct *p)
131{ return 0; } 145{ return 0; }
146static inline void delayacct_freepages_start(void)
147{}
148static inline void delayacct_freepages_end(void)
149{}
150
132#endif /* CONFIG_TASK_DELAY_ACCT */ 151#endif /* CONFIG_TASK_DELAY_ACCT */
133 152
134#endif 153#endif
diff --git a/include/linux/sched.h b/include/linux/sched.h
index d22ffe06d0eb..42036ffe6b00 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -672,6 +672,10 @@ struct task_delay_info {
672 /* io operations performed */ 672 /* io operations performed */
673 u32 swapin_count; /* total count of the number of swapin block */ 673 u32 swapin_count; /* total count of the number of swapin block */
674 /* io operations performed */ 674 /* io operations performed */
675
676 struct timespec freepages_start, freepages_end;
677 u64 freepages_delay; /* wait for memory reclaim */
678 u32 freepages_count; /* total count of memory reclaim */
675}; 679};
676#endif /* CONFIG_TASK_DELAY_ACCT */ 680#endif /* CONFIG_TASK_DELAY_ACCT */
677 681