* + delayacct-clear-right-tasks-flag-after-blkio-completes.patch added to -mm tree
@ 2021-04-15 20:42 akpm
0 siblings, 0 replies; only message in thread
From: akpm @ 2021-04-15 20:42 UTC (permalink / raw)
To: mm-commits, tj, mingo, joshs, axboe, laoar.shao
The patch titled
Subject: delayacct: clear right task's flag after blkio completes
has been added to the -mm tree. Its filename is
delayacct-clear-right-tasks-flag-after-blkio-completes.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/delayacct-clear-right-tasks-flag-after-blkio-completes.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/delayacct-clear-right-tasks-flag-after-blkio-completes.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Yafang Shao <laoar.shao@gmail.com>
Subject: delayacct: clear right task's flag after blkio completes
When I was implementing a latency analyze tool by using task->delays and
other things, I found there's issue in delayacct. The issue is it should
clear the target's flag instead of current's in delayacct_blkio_end().
When I git blame delayacct, I found there're some similar issues we have
fixed in delayacct_blkio_end().
'Commit c96f5471ce7d ("delayacct: Account blkio completion on the correct task")'
fixed the issue that it should account blkio completion on the target
task instead of current.
'Commit b512719f771a ("delayacct: fix crash in delayacct_blkio_end() after delayacct init failure")'
fixed the issue that it should check target task's delays instead of
current task'. It seems that delayacct_blkio_{begin, end} are error prone.
So I introduce a new paratmeter - the target task 'p' into these helpers,
after that change, the callsite will specifilly set the right task, which
should make it less error prone.
Link: https://lkml.kernel.org/r/20210414083720.24083-1-laoar.shao@gmail.com
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Josh Snyder <joshs@netflix.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
include/linux/delayacct.h | 20 ++++++++++----------
mm/memory.c | 8 ++++----
2 files changed, 14 insertions(+), 14 deletions(-)
--- a/include/linux/delayacct.h~delayacct-clear-right-tasks-flag-after-blkio-completes
+++ a/include/linux/delayacct.h
@@ -82,16 +82,16 @@ static inline int delayacct_is_task_wait
return 0;
}
-static inline void delayacct_set_flag(int flag)
+static inline void delayacct_set_flag(struct task_struct *p, int flag)
{
- if (current->delays)
- current->delays->flags |= flag;
+ if (p->delays)
+ p->delays->flags |= flag;
}
-static inline void delayacct_clear_flag(int flag)
+static inline void delayacct_clear_flag(struct task_struct *p, int flag)
{
- if (current->delays)
- current->delays->flags &= ~flag;
+ if (p->delays)
+ p->delays->flags &= ~flag;
}
static inline void delayacct_tsk_init(struct task_struct *tsk)
@@ -114,7 +114,7 @@ static inline void delayacct_tsk_free(st
static inline void delayacct_blkio_start(void)
{
- delayacct_set_flag(DELAYACCT_PF_BLKIO);
+ delayacct_set_flag(current, DELAYACCT_PF_BLKIO);
if (current->delays)
__delayacct_blkio_start();
}
@@ -123,7 +123,7 @@ static inline void delayacct_blkio_end(s
{
if (p->delays)
__delayacct_blkio_end(p);
- delayacct_clear_flag(DELAYACCT_PF_BLKIO);
+ delayacct_clear_flag(p, DELAYACCT_PF_BLKIO);
}
static inline int delayacct_add_tsk(struct taskstats *d,
@@ -166,9 +166,9 @@ static inline void delayacct_thrashing_e
}
#else
-static inline void delayacct_set_flag(int flag)
+static inline void delayacct_set_flag(struct task_struct *p, int flag)
{}
-static inline void delayacct_clear_flag(int flag)
+static inline void delayacct_clear_flag(struct task_struct *p, int flag)
{}
static inline void delayacct_init(void)
{}
--- a/mm/memory.c~delayacct-clear-right-tasks-flag-after-blkio-completes
+++ a/mm/memory.c
@@ -3339,7 +3339,7 @@ vm_fault_t do_swap_page(struct vm_fault
}
- delayacct_set_flag(DELAYACCT_PF_SWAPIN);
+ delayacct_set_flag(current, DELAYACCT_PF_SWAPIN);
page = lookup_swap_cache(entry, vma, vmf->address);
swapcache = page;
@@ -3388,7 +3388,7 @@ vm_fault_t do_swap_page(struct vm_fault
vmf->address, &vmf->ptl);
if (likely(pte_same(*vmf->pte, vmf->orig_pte)))
ret = VM_FAULT_OOM;
- delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
+ delayacct_clear_flag(current, DELAYACCT_PF_SWAPIN);
goto unlock;
}
@@ -3402,13 +3402,13 @@ vm_fault_t do_swap_page(struct vm_fault
* owner processes (which may be unknown at hwpoison time)
*/
ret = VM_FAULT_HWPOISON;
- delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
+ delayacct_clear_flag(current, DELAYACCT_PF_SWAPIN);
goto out_release;
}
locked = lock_page_or_retry(page, vma->vm_mm, vmf->flags);
- delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
+ delayacct_clear_flag(current, DELAYACCT_PF_SWAPIN);
if (!locked) {
ret |= VM_FAULT_RETRY;
goto out_release;
_
Patches currently in -mm which might be from laoar.shao@gmail.com are
delayacct-clear-right-tasks-flag-after-blkio-completes.patch
^ permalink raw reply [flat|nested] only message in thread
only message in thread, other threads:[~2021-04-15 20:42 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-04-15 20:42 + delayacct-clear-right-tasks-flag-after-blkio-completes.patch added to -mm tree akpm
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).