0ff922452d
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>
95 lines
2.4 KiB
C
95 lines
2.4 KiB
C
/* delayacct.h - per-task delay accounting
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*
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* Copyright (C) Shailabh Nagar, IBM Corp. 2006
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
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* the GNU General Public License for more details.
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*
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*/
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#ifndef _LINUX_DELAYACCT_H
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#define _LINUX_DELAYACCT_H
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#include <linux/sched.h>
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/*
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* Per-task flags relevant to delay accounting
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* maintained privately to avoid exhausting similar flags in sched.h:PF_*
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* Used to set current->delays->flags
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*/
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#define DELAYACCT_PF_SWAPIN 0x00000001 /* I am doing a swapin */
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#ifdef CONFIG_TASK_DELAY_ACCT
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extern int delayacct_on; /* Delay accounting turned on/off */
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extern kmem_cache_t *delayacct_cache;
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extern void delayacct_init(void);
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extern void __delayacct_tsk_init(struct task_struct *);
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extern void __delayacct_tsk_exit(struct task_struct *);
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extern void __delayacct_blkio_start(void);
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extern void __delayacct_blkio_end(void);
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static inline void delayacct_set_flag(int flag)
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{
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if (current->delays)
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current->delays->flags |= flag;
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}
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static inline void delayacct_clear_flag(int flag)
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{
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if (current->delays)
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current->delays->flags &= ~flag;
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}
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static inline void delayacct_tsk_init(struct task_struct *tsk)
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{
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/* reinitialize in case parent's non-null pointer was dup'ed*/
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tsk->delays = NULL;
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if (unlikely(delayacct_on))
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__delayacct_tsk_init(tsk);
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}
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static inline void delayacct_tsk_exit(struct task_struct *tsk)
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{
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if (tsk->delays)
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__delayacct_tsk_exit(tsk);
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}
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static inline void delayacct_blkio_start(void)
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{
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if (current->delays)
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__delayacct_blkio_start();
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}
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static inline void delayacct_blkio_end(void)
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{
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if (current->delays)
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__delayacct_blkio_end();
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}
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#else
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static inline void delayacct_set_flag(int flag)
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{}
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static inline void delayacct_clear_flag(int flag)
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{}
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static inline void delayacct_init(void)
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{}
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static inline void delayacct_tsk_init(struct task_struct *tsk)
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{}
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static inline void delayacct_tsk_exit(struct task_struct *tsk)
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{}
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static inline void delayacct_blkio_start(void)
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{}
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static inline void delayacct_blkio_end(void)
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{}
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#endif /* CONFIG_TASK_DELAY_ACCT */
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#endif
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