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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-18 17:39:59 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-18 17:39:59 +0000 |
commit | 27d3313807296c3943a96ceef8c2b7279cb56962 (patch) | |
tree | 7d08e78c36ab6437b403fc7cd8c23e41f135c7a3 /debian/patches-rt/0001-signal-Add-proper-comment-about-the-preempt-disable-.patch | |
parent | Merging upstream version 6.7.7. (diff) | |
download | linux-27d3313807296c3943a96ceef8c2b7279cb56962.tar.xz linux-27d3313807296c3943a96ceef8c2b7279cb56962.zip |
Adding debian version 6.7.7-1.debian/6.7.7-1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'debian/patches-rt/0001-signal-Add-proper-comment-about-the-preempt-disable-.patch')
-rw-r--r-- | debian/patches-rt/0001-signal-Add-proper-comment-about-the-preempt-disable-.patch | 47 |
1 files changed, 0 insertions, 47 deletions
diff --git a/debian/patches-rt/0001-signal-Add-proper-comment-about-the-preempt-disable-.patch b/debian/patches-rt/0001-signal-Add-proper-comment-about-the-preempt-disable-.patch deleted file mode 100644 index e00261d790..0000000000 --- a/debian/patches-rt/0001-signal-Add-proper-comment-about-the-preempt-disable-.patch +++ /dev/null @@ -1,47 +0,0 @@ -From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> -Date: Thu, 3 Aug 2023 12:09:31 +0200 -Subject: [PATCH 1/2] signal: Add proper comment about the preempt-disable in - ptrace_stop(). -Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.6/older/patches-6.6.7-rt18.tar.xz - -Commit 53da1d9456fe7 ("fix ptrace slowness") added a preempt-disable section -between read_unlock() and the following schedule() invocation without -explaining why it is needed. - -Replace the comment with an explanation why this is needed. Clarify that -it is needed for correctness but for performance reasons. - -Acked-by: Oleg Nesterov <oleg@redhat.com> -Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> -Link: https://lore.kernel.org/r/20230803100932.325870-2-bigeasy@linutronix.de ---- - kernel/signal.c | 17 ++++++++++++++--- - 1 file changed, 14 insertions(+), 3 deletions(-) - ---- a/kernel/signal.c -+++ b/kernel/signal.c -@@ -2329,10 +2329,21 @@ static int ptrace_stop(int exit_code, in - do_notify_parent_cldstop(current, false, why); - - /* -- * Don't want to allow preemption here, because -- * sys_ptrace() needs this task to be inactive. -+ * The previous do_notify_parent_cldstop() invocation woke ptracer. -+ * One a PREEMPTION kernel this can result in preemption requirement -+ * which will be fulfilled after read_unlock() and the ptracer will be -+ * put on the CPU. -+ * The ptracer is in wait_task_inactive(, __TASK_TRACED) waiting for -+ * this task wait in schedule(). If this task gets preempted then it -+ * remains enqueued on the runqueue. The ptracer will observe this and -+ * then sleep for a delay of one HZ tick. In the meantime this task -+ * gets scheduled, enters schedule() and will wait for the ptracer. - * -- * XXX: implement read_unlock_no_resched(). -+ * This preemption point is not bad from correctness point of view but -+ * extends the runtime by one HZ tick time due to the ptracer's sleep. -+ * The preempt-disable section ensures that there will be no preemption -+ * between unlock and schedule() and so improving the performance since -+ * the ptracer has no reason to sleep. - */ - preempt_disable(); - read_unlock(&tasklist_lock); |