summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorYafang Shao <laoar.shao@gmail.com>2021-05-06 18:05:00 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-05-07 00:26:32 -0700
commit3d1c7fd97e4c5e54034231cd11319079dfaed60e (patch)
tree67646d7c01ebe0a3f3b02a0e9eae55e9be9730d0
parent6f1f942cd5fbbe308f912fc84e3f10fbc8113a68 (diff)
delayacct: clear right task's flag after blkio completes
When I was implementing a latency analyzer tool by using task->delays and other things, I found an 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' - to 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> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/delayacct.h20
-rw-r--r--mm/memory.c8
2 files changed, 14 insertions, 14 deletions
diff --git a/include/linux/delayacct.h b/include/linux/delayacct.h
index 2d3bdcccf5eb..21651f946751 100644
--- a/include/linux/delayacct.h
+++ b/include/linux/delayacct.h
@@ -82,16 +82,16 @@ static inline int delayacct_is_task_waiting_on_io(struct task_struct *p)
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(struct task_struct *tsk)
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(struct task_struct *p)
{
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_end(void)
}
#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)
{}
diff --git a/mm/memory.c b/mm/memory.c
index cbdc2cd9cedb..8c491f813687 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3339,7 +3339,7 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
}
- 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)
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 *vmf)
* 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;