From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 528013F4119; Thu, 14 May 2026 19:36:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.40.44.13 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778787397; cv=none; b=PAP5cIGAUL0Qr0trTgFaA3OSARzW6G+OZmr3X6MaRRhRmy5RsNGM9lssfNRVKvy94zFhV4D1VRzftqbJOZHpmJrUvqfiJ/uceK3SDz8/iXRwa/YJOCNNy2u0/aQAiwqXO15nh1XcygKMseLhy54vRjF8gTCk1rFp/jOycal8wmM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778787397; c=relaxed/simple; bh=Mx4wtsH5+NjyGsP/HE01zzfsENrVvwY5wlHkuUFnPrw=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=CujVR74+e9JpciEXvmHurZXBkVq/su9w4u7Gk4DQvIcUqLAeq4GCB2dlGIN271JGWlqcaNQB7CGXxMy6sWdw7AVRCFnKYbFP9IZuUxk47UPX09tKbUELm6FpdKmrGxv/DDRjC+ovCT+MHLweqRMt2rtiLwkOfHYWnOfENidNzto= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=goodmis.org; spf=pass smtp.mailfrom=goodmis.org; arc=none smtp.client-ip=216.40.44.13 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=goodmis.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=goodmis.org Received: from omf07.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay05.hostedemail.com (Postfix) with ESMTP id C5B2B405BD; Thu, 14 May 2026 19:36:33 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: rostedt@goodmis.org) by omf07.hostedemail.com (Postfix) with ESMTPA id B8B212002E; Thu, 14 May 2026 19:36:31 +0000 (UTC) Date: Thu, 14 May 2026 15:36:37 -0400 From: Steven Rostedt To: Yiyang Chen Cc: peterz@infradead.org, mingo@redhat.com, vincent.guittot@linaro.org, mhiramat@kernel.org, mathieu.desnoyers@efficios.com, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Subject: Re: [PATCH] sched/clock: Provide !HAVE_UNSTABLE_SCHED_CLOCK stub for sched_clock_stable() Message-ID: <20260514153637.553ad41c@gandalf.local.home> In-Reply-To: <56e45338858946cd9581b75c8bd45dd37dba52c5.1778773587.git.cyyzero16@gmail.com> References: <56e45338858946cd9581b75c8bd45dd37dba52c5.1778773587.git.cyyzero16@gmail.com> X-Mailer: Claws Mail 3.20.0git84 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Stat-Signature: gxr33t5ff35t4azr9w4tmcwge7tb73ek X-Rspamd-Server: rspamout02 X-Rspamd-Queue-Id: B8B212002E X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX1+xv7vj7iHDSN5VcmAmfB14CdK6qaC/ngg= X-HE-Tag: 1778787391-588625 X-HE-Meta: U2FsdGVkX1+cy0D4gWks1x+FrLK8C4ogBqctE6FEgtBIyvebx6yUr0mhmcxNX/+vf9+S6KeaZB98ZHfK3bk8jXIsNJVC5WikbCFOrEdVXj7c1NYOW+USlCOSY3Tpy0DjzcNvVUtGkKtVYILfqrQQjCaWDI0VRL5ppmWfRF2kVdz0dnNUbPxHHUZG9c2FJYuIwAD/l1ehjt6Ey+eeHGKeGbBf3dxNuNDZ4bbsTZLFHO74wRkhe8iC/0+VEYj7HH5xTq+Zz3XV4Hb+Dvv6wP+xDdGL7JKTcq6pE7YZ4+J/zyWr/myGE64gSZts10Ts7HeFDt1sQf8rnYe7FMbPTUKjMHsosC6bVJyI/NgiOMZpbBYxpwppjtzza6n0+hbBAxkq1mWwxXEXQc8QG2Yuv01qZA== On Fri, 15 May 2026 00:05:05 +0800 Yiyang Chen wrote: > When CONFIG_HAVE_UNSTABLE_SCHED_CLOCK is disabled, sched_clock() is > already assumed to provide stable semantics, but the public header > doesn't provide a sched_clock_stable() stub for that case. > > Add a header stub that always returns true and clean up the duplicate > local stub in ring_buffer.c, so callers can use sched_clock_stable() > unconditionally. > > Signed-off-by: Yiyang Chen > --- > include/linux/sched/clock.h | 5 +++++ > kernel/trace/ring_buffer.c | 7 ------- > 2 files changed, 5 insertions(+), 7 deletions(-) > > diff --git a/include/linux/sched/clock.h b/include/linux/sched/clock.h > index 196f0ca351a2..39f0a7f94bfc 100644 > --- a/include/linux/sched/clock.h > +++ b/include/linux/sched/clock.h > @@ -33,6 +33,11 @@ extern u64 sched_clock_cpu(int cpu); > extern void sched_clock_init(void); > > #ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK > +static inline int sched_clock_stable(void) > +{ > + return 1; > +} > + > static inline void sched_clock_tick(void) > { > } > diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c > index 5326924615a4..02691c3c6dd6 100644 > --- a/kernel/trace/ring_buffer.c > +++ b/kernel/trace/ring_buffer.c > @@ -3769,13 +3769,6 @@ rb_add_time_stamp(struct ring_buffer_per_cpu *cpu_buffer, > return skip_time_extend(event); > } > > -#ifndef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK > -static inline bool sched_clock_stable(void) > -{ > - return true; > -} > -#endif > - > static void > rb_check_timestamp(struct ring_buffer_per_cpu *cpu_buffer, > struct rb_event_info *info) Thanks for moving this out of the ring buffer code. Acked-by: Steven Rostedt -- Steve