Skip to content

block: invalidate cached plug timestamp on context switch #971

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
blktests-ci wants to merge 2 commits into
base: linus-master_base
Choose a base branch
from
+15 −14
Open

block: invalidate cached plug timestamp on context switch #971

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
bf8e554
kernel/fork: clear PF_BLOCK_TS in copy_process()
Jun 16, 2026
cd54261
block: invalidate cached plug timestamp after task switch
Jun 16, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
16 changes: 6 additions & 10 deletions include/linux/blkdev.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1222,16 +1222,12 @@ static inline void blk_flush_plug(struct blk_plug *plug, bool async)
__blk_flush_plug(plug, async);
}

/*
* tsk == current here
*/
static inline void blk_plug_invalidate_ts(struct task_struct *tsk)
static __always_inline void blk_plug_invalidate_ts(void)
{
struct blk_plug *plug = tsk->plug;

if (plug)
plug->cur_ktime = 0;
current->flags &= ~PF_BLOCK_TS;
if (unlikely(current->flags & PF_BLOCK_TS)) {
current->plug->cur_ktime = 0;
current->flags &= ~PF_BLOCK_TS;
}
}

int blkdev_issue_flush(struct block_device *bdev);
Expand All @@ -1257,7 +1253,7 @@ static inline void blk_flush_plug(struct blk_plug *plug, bool async)
{
}

static inline void blk_plug_invalidate_ts(struct task_struct *tsk)
static inline void blk_plug_invalidate_ts(void)
{
}

Expand Down
1 change: 1 addition & 0 deletions kernel/fork.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2338,6 +2338,7 @@ __latent_entropy struct task_struct *copy_process(

#ifdef CONFIG_BLOCK
p->plug = NULL;
p->flags &= ~PF_BLOCK_TS;
#endif
futex_init_task(p);

Expand Down
12 changes: 8 additions & 4 deletions kernel/sched/core.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -5368,6 +5368,12 @@ static struct rq *finish_task_switch(struct task_struct *prev)
*/
kmap_local_sched_in();

/*
* Any cached block-layer timestamp (plug->cur_ktime) is stale now,
* invalidate it.
*/
blk_plug_invalidate_ts();

fire_sched_in_preempt_notifiers(current);
/*
* When switching through a kernel thread, the loop in
Expand Down Expand Up @@ -7290,12 +7296,10 @@ static inline void sched_submit_work(struct task_struct *tsk)

static void sched_update_worker(struct task_struct *tsk)
{
if (tsk->flags & (PF_WQ_WORKER | PF_IO_WORKER | PF_BLOCK_TS)) {
if (tsk->flags & PF_BLOCK_TS)
blk_plug_invalidate_ts(tsk);
if (tsk->flags & (PF_WQ_WORKER | PF_IO_WORKER)) {
if (tsk->flags & PF_WQ_WORKER)
wq_worker_running(tsk);
else if (tsk->flags & PF_IO_WORKER)
else
io_wq_worker_running(tsk);
}
}
Expand Down
Loading