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authorShailabh Nagar <nagar@watson.ibm.com>2006-07-14 00:24:37 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-07-14 21:53:56 -0700
commit0ff922452df86f3e9a2c6f705c4588ec62d096a7 (patch)
treeac84041bfb63f12d0e2db733c46b2cd2438b4882 /include/linux/delayacct.h
parentca74e92b4698276b6696f15a801759f50944f387 (diff)
downloadlwn-0ff922452df86f3e9a2c6f705c4588ec62d096a7.tar.gz
lwn-0ff922452df86f3e9a2c6f705c4588ec62d096a7.zip
[PATCH] per-task-delay-accounting: sync block I/O and swapin delay collection
Unlike earlier iterations of the delay accounting patches, now delays are only collected for the actual I/O waits rather than try and cover the delays seen in I/O submission paths. Account separately for block I/O delays incurred as a result of swapin page faults whose frequency can be affected by the task/process' rss limit. Hence swapin delays can act as feedback for rss limit changes independent of I/O priority changes. Signed-off-by: Shailabh Nagar <nagar@watson.ibm.com> Signed-off-by: Balbir Singh <balbir@in.ibm.com> Cc: Jes Sorensen <jes@sgi.com> Cc: Peter Chubb <peterc@gelato.unsw.edu.au> Cc: Erich Focht <efocht@ess.nec.de> Cc: Levent Serinol <lserinol@gmail.com> Cc: Jay Lan <jlan@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include/linux/delayacct.h')
-rw-r--r--include/linux/delayacct.h25
1 files changed, 25 insertions, 0 deletions
diff --git a/include/linux/delayacct.h b/include/linux/delayacct.h
index 9572cfa1f129..0ecbf9aad8e1 100644
--- a/include/linux/delayacct.h
+++ b/include/linux/delayacct.h
@@ -19,6 +19,13 @@
#include <linux/sched.h>
+/*
+ * Per-task flags relevant to delay accounting
+ * maintained privately to avoid exhausting similar flags in sched.h:PF_*
+ * Used to set current->delays->flags
+ */
+#define DELAYACCT_PF_SWAPIN 0x00000001 /* I am doing a swapin */
+
#ifdef CONFIG_TASK_DELAY_ACCT
extern int delayacct_on; /* Delay accounting turned on/off */
@@ -26,6 +33,8 @@ extern kmem_cache_t *delayacct_cache;
extern void delayacct_init(void);
extern void __delayacct_tsk_init(struct task_struct *);
extern void __delayacct_tsk_exit(struct task_struct *);
+extern void __delayacct_blkio_start(void);
+extern void __delayacct_blkio_end(void);
static inline void delayacct_set_flag(int flag)
{
@@ -53,6 +62,18 @@ static inline void delayacct_tsk_exit(struct task_struct *tsk)
__delayacct_tsk_exit(tsk);
}
+static inline void delayacct_blkio_start(void)
+{
+ if (current->delays)
+ __delayacct_blkio_start();
+}
+
+static inline void delayacct_blkio_end(void)
+{
+ if (current->delays)
+ __delayacct_blkio_end();
+}
+
#else
static inline void delayacct_set_flag(int flag)
{}
@@ -64,6 +85,10 @@ static inline void delayacct_tsk_init(struct task_struct *tsk)
{}
static inline void delayacct_tsk_exit(struct task_struct *tsk)
{}
+static inline void delayacct_blkio_start(void)
+{}
+static inline void delayacct_blkio_end(void)
+{}
#endif /* CONFIG_TASK_DELAY_ACCT */
#endif