From: Karl Mehltretter <kmehltretter@gmail.com>
To: Steven Rostedt <rostedt@goodmis.org>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@kernel.org>
Cc: Karl Mehltretter <kmehltretter@gmail.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Ingo Molnar <mingo@redhat.com>, Andy Lutomirski <luto@kernel.org>,
Frederic Weisbecker <frederic@kernel.org>,
"Paul E . McKenney" <paulmck@kernel.org>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Boqun Feng <boqun@kernel.org>, Waiman Long <longman@redhat.com>,
Juri Lelli <juri.lelli@redhat.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
Valentin Schneider <vschneid@redhat.com>,
K Prateek Nayak <kprateek.nayak@amd.com>,
Hongyan Xia <hongyan.xia@transsion.com>,
Jonathan Corbet <corbet@lwn.net>,
Shuah Khan <skhan@linuxfoundation.org>,
Randy Dunlap <rdunlap@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>,
Nathan Chancellor <nathan@kernel.org>,
Nick Desaulniers <ndesaulniers@google.com>,
Bill Wendling <morbo@google.com>,
Justin Stitt <justinstitt@google.com>,
linux-arm-kernel@lists.infradead.org,
linux-trace-kernel@vger.kernel.org,
linux-rt-devel@lists.linux.dev, linux-doc@vger.kernel.org,
llvm@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: [RFC PATCH 04/12] entry: Skip inactive IRQ-return reschedule calls
Date: Thu, 22 Oct 2026 07:16:46 +0200 [thread overview]
Message-ID: <20261022051654.79224-5-kmehltretter@gmail.com> (raw)
In-Reply-To: <20261022051654.79224-1-kmehltretter@gmail.com>
irqentry_exit_to_kernel_mode_preempt() calls the dynamic reschedule helper
when preemption is enabled even if the preempt count is nonzero. The helper
returns immediately, but its call and return remain traceable after hardirq
context has been removed.
Check the preempt count in the inline caller and avoid the inactive call.
Keep the existing check in the helper for its other callers. This does not
change whether IRQ return schedules.
Assisted-by: LLM
---
include/linux/irq-entry-common.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/irq-entry-common.h b/include/linux/irq-entry-common.h
index 3ee80e926a17a..24c2b9fdff4f4 100644
--- a/include/linux/irq-entry-common.h
+++ b/include/linux/irq-entry-common.h
@@ -487,7 +487,7 @@ static inline void irqentry_exit_to_kernel_mode_preempt(struct pt_regs *regs,
if (regs_irqs_disabled(regs) || state.exit_rcu)
return;
- if (IS_ENABLED(CONFIG_PREEMPTION))
+ if (IS_ENABLED(CONFIG_PREEMPTION) && !preempt_count())
irqentry_exit_cond_resched();
}
--
2.39.5 (Apple Git-154)
next prev parent reply other threads:[~2026-10-22 5:17 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-22 5:16 [RFC PATCH 00/12] entry, tracing: Classify early hardirq entry and return tails Karl Mehltretter
2026-10-22 5:16 ` [RFC PATCH 01/12] sched: Split preempt-count bookkeeping from raw updates Karl Mehltretter
2026-10-22 5:16 ` [RFC PATCH 02/12] lockdep: Use raw access for pinned hardirq state Karl Mehltretter
2026-10-22 5:16 ` [RFC PATCH 03/12] entry: Add the pre-counted ordinary-hardirq entry/exit contract Karl Mehltretter
2026-10-22 5:16 ` Karl Mehltretter [this message]
2026-10-22 5:16 ` [RFC PATCH 05/12] context_tracking: Split IRQ-exit preparation from the EQS transition Karl Mehltretter
2026-10-22 5:16 ` [RFC PATCH 06/12] lockdep: Prepare IRQ-on state from a hardirq return tail Karl Mehltretter
2026-10-22 5:16 ` [RFC PATCH 07/12] entry: Carry ordinary-hardirq provenance through kernel return Karl Mehltretter
2026-10-22 5:16 ` [RFC PATCH 08/12] entry: Classify ordinary hardirq return-tail work as hardirq context Karl Mehltretter
2026-10-22 5:16 ` [RFC PATCH 09/12] arm64: Use the pre-counted hardirq lifecycle Karl Mehltretter
2026-10-22 5:16 ` [RFC PATCH 10/12] docs: entry: Describe " Karl Mehltretter
2026-10-22 5:16 ` [RFC PATCH 11/12] locking/selftest: Exercise hardirq return-tail preparation Karl Mehltretter
2026-10-22 5:16 ` [RFC PATCH 12/12] tracing: Pin recursion state for its complete lifetime Karl Mehltretter
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20261022051654.79224-5-kmehltretter@gmail.com \
--to=kmehltretter@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=bigeasy@linutronix.de \
--cc=boqun@kernel.org \
--cc=bsegall@google.com \
--cc=catalin.marinas@arm.com \
--cc=corbet@lwn.net \
--cc=dietmar.eggemann@arm.com \
--cc=frederic@kernel.org \
--cc=hongyan.xia@transsion.com \
--cc=juri.lelli@redhat.com \
--cc=justinstitt@google.com \
--cc=kprateek.nayak@amd.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-doc@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-rt-devel@lists.linux.dev \
--cc=linux-trace-kernel@vger.kernel.org \
--cc=llvm@lists.linux.dev \
--cc=longman@redhat.com \
--cc=luto@kernel.org \
--cc=mark.rutland@arm.com \
--cc=mgorman@suse.de \
--cc=mingo@redhat.com \
--cc=morbo@google.com \
--cc=nathan@kernel.org \
--cc=ndesaulniers@google.com \
--cc=paulmck@kernel.org \
--cc=peterz@infradead.org \
--cc=rdunlap@infradead.org \
--cc=rostedt@goodmis.org \
--cc=skhan@linuxfoundation.org \
--cc=tglx@kernel.org \
--cc=vincent.guittot@linaro.org \
--cc=vschneid@redhat.com \
--cc=will@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox