diff options
| author | John Stultz <jstultz@google.com> | 2026-05-12 02:56:16 +0000 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2026-06-02 12:26:07 +0200 |
| commit | 4c2a20413d7fb3fc3dd7adf233a4f82bb203fb58 (patch) | |
| tree | e4e25a83ca1a085ee86392c2dc82a1f8b9de39a4 /include/linux | |
| parent | f13beb010e4ab0735c9e46802cbcc820a8bd6467 (diff) | |
sched: Add is_blocked task flag
Add a new is_blocked flag to the task struct. This flag is set
by try_to_block_task() and cleared by ttwu_do_wakeup() and
tracks if the task is blocked.
Traditionally this would mirror !p->on_rq, however due things
like DELAY_DEQUEUE and PROXY_EXEC, this can diverge, so its
useful to manage separately.
Additionally with this, we might be able to get rid of the
p->se.sched_delayed (ab)use in the core code (eventually).
Taken whole cloth from Peter's email:
https://lore.kernel.org/lkml/20260501132143.GC1026330@noisy.programming.kicks-ass.net/
With a few additional p->is_blocked = 0 in a few cases where
we return current if blocked_on gets zeroed or there is
no owner. This may hint that these current special cases
might be dropped eventually.
This change also helps resolve wait-queue stalls seen with
proxy-execution. See previous patch attempts for details:
https://lore.kernel.org/lkml/20260430215103.2978955-2-jstultz@google.com/
Reported-by: Vineeth Pillai <vineethrp@google.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: John Stultz <jstultz@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260512025635.2840817-7-jstultz@google.com
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/sched.h | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index 5dea5b10ac99..ec170663f99b 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -852,7 +852,11 @@ struct task_struct { struct alloc_tag *alloc_tag; #endif - int on_cpu; + u8 on_cpu; + u8 on_rq; + u8 is_blocked; + u8 __pad; + struct __call_single_node wake_entry; unsigned int wakee_flips; unsigned long wakee_flip_decay_ts; @@ -867,7 +871,6 @@ struct task_struct { */ int recent_used_cpu; int wake_cpu; - int on_rq; int prio; int static_prio; |