diff options
| author | Tejun Heo <tj@kernel.org> | 2026-05-10 12:51:09 -1000 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2026-05-10 12:51:09 -1000 |
| commit | b5646c627652241f248f0a4ff31b1d32316b0068 (patch) | |
| tree | fb4c2b67c5ad7662894a77fa1ca540b7716fdd25 /include/linux/sched | |
| parent | f25ad1e3cbaa4c87bb2b11496786f79db54c294f (diff) | |
| parent | d3e73a0808ddfb91ac36cd548643cbbeb00ad4db (diff) | |
| download | linux-next-b5646c627652241f248f0a4ff31b1d32316b0068.tar.gz linux-next-b5646c627652241f248f0a4ff31b1d32316b0068.zip | |
Merge branch 'for-7.1-fixes' into for-7.2
Conflict between:
[1] 41e3312861ea ("sched_ext: add p->scx.tid and SCX_OPS_TID_TO_TASK lookup")
[2] c941d7391f25 ("sched_ext: Close root-enable vs sched_ext_dead() race with SCX_TASK_INIT_BEGIN")
in scx_root_enable_workfn()'s post-init block. [1] added a tid hash
insertion under a scoped_guard() for scx_tasks_lock; [2] wraps the same
region in task_rq_lock() for a DEAD recheck. A naive merge would invert the
iter's outer/inner order.
[3] f25ad1e3cbaa ("sched_ext: Add scx_task_iter_relock() and use it in scx_root_enable_workfn()")
was added to for-7.2 for a clean resolution: scx_task_iter_relock(iter, p)
takes both scx_tasks_lock and @p's rq lock in iter order.
Resolved by routing both sides through [3]'s dual-lock helper: the post-init
region runs under a single scx_task_iter_relock() acquisition, with [2]'s
state machine and [1]'s hash insert in sequence inside it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'include/linux/sched')
| -rw-r--r-- | include/linux/sched/ext.h | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/include/linux/sched/ext.h b/include/linux/sched/ext.h index d05efcac794d..20b2343aa344 100644 --- a/include/linux/sched/ext.h +++ b/include/linux/sched/ext.h @@ -103,21 +103,25 @@ enum scx_ent_flags { SCX_TASK_IMMED = 1 << 5, /* task is on local DSQ with %SCX_ENQ_IMMED */ /* - * Bits 8 and 9 are used to carry task state: + * Bits 8 to 10 are used to carry task state: * * NONE ops.init_task() not called yet + * INIT_BEGIN ops.init_task() in flight; see sched_ext_dead() * INIT ops.init_task() succeeded, but task can be cancelled * READY fully initialized, but not in sched_ext * ENABLED fully initialized and in sched_ext + * DEAD terminal state set by sched_ext_dead() */ - SCX_TASK_STATE_SHIFT = 8, /* bits 8 and 9 are used to carry task state */ - SCX_TASK_STATE_BITS = 2, + SCX_TASK_STATE_SHIFT = 8, + SCX_TASK_STATE_BITS = 3, SCX_TASK_STATE_MASK = ((1 << SCX_TASK_STATE_BITS) - 1) << SCX_TASK_STATE_SHIFT, SCX_TASK_NONE = 0 << SCX_TASK_STATE_SHIFT, - SCX_TASK_INIT = 1 << SCX_TASK_STATE_SHIFT, - SCX_TASK_READY = 2 << SCX_TASK_STATE_SHIFT, - SCX_TASK_ENABLED = 3 << SCX_TASK_STATE_SHIFT, + SCX_TASK_INIT_BEGIN = 1 << SCX_TASK_STATE_SHIFT, + SCX_TASK_INIT = 2 << SCX_TASK_STATE_SHIFT, + SCX_TASK_READY = 3 << SCX_TASK_STATE_SHIFT, + SCX_TASK_ENABLED = 4 << SCX_TASK_STATE_SHIFT, + SCX_TASK_DEAD = 5 << SCX_TASK_STATE_SHIFT, /* * Bits 12 and 13 are used to carry reenqueue reason. In addition to |