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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-10-31 06:03:32 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-10-31 06:03:32 +0300 |
| commit | 9cc6fea175e41580000419a90fa744ba46aa4722 (patch) | |
| tree | fcb4aa5c2a67862d9a415f1aa67dede57c5173fb /drivers | |
| parent | ecb8cd2a9f7af7f99a6d4fa0a5a31822f6cfe255 (diff) | |
| parent | 1aabbc532413ced293952f8e149ad0a607d6e470 (diff) | |
| download | linux-9cc6fea175e41580000419a90fa744ba46aa4722.tar.xz | |
Merge tag 'core-core-2023-10-29-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core updates from Thomas Gleixner:
"Two small updates to ptrace_stop():
- Add a comment to explain that the preempt_disable() before
unlocking tasklist lock is not a correctness problem and just
avoids the tracer to preempt the tracee before the tracee schedules
out.
- Make that preempt_disable() conditional on PREEMPT_RT=n.
RT enabled kernels cannot disable preemption at this point because
cgroup_enter_frozen() and sched_submit_work() acquire spinlocks or
rwlocks which are substituted by sleeping locks on RT. Acquiring a
sleeping lock in a preemption disable region is obviously not
possible.
This obviously brings back the potential slowdown of ptrace() for
RT enabled kernels, but that's a price to be paid for latency
guarantees"
* tag 'core-core-2023-10-29-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
signal: Don't disable preemption in ptrace_stop() on PREEMPT_RT
signal: Add a proper comment about preempt_disable() in ptrace_stop()
Diffstat (limited to 'drivers')
0 files changed, 0 insertions, 0 deletions