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 894473D8108 for ; Wed, 18 Mar 2026 14:13:22 +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=1773843204; cv=none; b=U/qYknrBBb/Hdzjn+saewm4Ks1AkUanC4Odt94geHg44N6cCRzNMmjlxf3Mzc0FOEBnZbV9gEaJ7+z7rZeQUv0+MlpB1A4tCs5fkuKUf5DIJaXldTc3LgwyQZbHw6IPU+XUGWG48J/+85o7ezphmqTqyFHahiYt75vcNJJCNyeQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773843204; c=relaxed/simple; bh=czbwyGqbozmeu8aQkUG1eMG3LdtVno01NK8w0fauwAk=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=U37uuXxX6AG08YMbUvj9EUAEs0gAUY9oPyBgBhc4GNPc4LXGZzgtQbu0xsbiJHrOZCTC8vJKi1ZSXv5LQSc4njdQs04v287EVDYPfExiWpJkqCrzpb/hPH+UIiNDAJqlbnfd5XOPjZ+TSXc35BMSo7cIK7V/zCBLrDQBiqpLFlc= 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 omf16.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 92DF21B83C4; Wed, 18 Mar 2026 14:13:20 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: rostedt@goodmis.org) by omf16.hostedemail.com (Postfix) with ESMTPA id AF23720013; Wed, 18 Mar 2026 14:13:17 +0000 (UTC) Date: Wed, 18 Mar 2026 10:13:45 -0400 From: Steven Rostedt To: "Chuyi Zhou" Cc: , , , , , , , , , , , Subject: Re: [PATCH v3 01/12] smp: Disable preemption explicitly in __csd_lock_wait Message-ID: <20260318101345.4c054e20@gandalf.local.home> In-Reply-To: <20260318045638.1572777-2-zhouchuyi@bytedance.com> References: <20260318045638.1572777-1-zhouchuyi@bytedance.com> <20260318045638.1572777-2-zhouchuyi@bytedance.com> X-Mailer: Claws Mail 3.20.0git84 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-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-Rspamd-Server: rspamout07 X-Rspamd-Queue-Id: AF23720013 X-Stat-Signature: dhxpxi5t48pcnxkzmsmhwo9dhtigoapu X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX19mS7ZNTlAruXBqqKl0gQIuQ/E2PvHnWyA= X-HE-Tag: 1773843197-697650 X-HE-Meta: U2FsdGVkX19bYUZb4AIzNtj8NM6HHyQ2bjLhPm2Mjj6nRxSPFqVFep+N1sBpKZ3uXWX4uIEtQPpMIv/LCWZlw5RcbdZ6RG+oJEB5QUtwJiBCHGbwyJ9KUpEMkvHOfTxEf789SADtOjFJkCLQ03sV1JOfqS0MSBhBI8674AViSop608gwc/PoTnxNSvb1mb0zOBtJavOW0Zf6FvQ5RBPuEu4Xm2S/+aqObGyu8pDG/MIok/iR+xERZCuFIrp2idBfPqJJVUt8agwJEtEiEyHbQKSVq5aRADvgfR9lunbesWn7qv7tF7FcHwZe6kCYtdAjyFnAuamV51fybDNLlSubJPgbdzgXw5I7eEao7atIl/5qPvuAIueznkmPrAqPGnhZw6mhBf8xpLc6mWH8auCJsg== On Wed, 18 Mar 2026 12:56:27 +0800 "Chuyi Zhou" wrote: > The latter patches will enable preemption before csd_lock_wait(), which > could break csdlock_debug. Because the slice of other tasks on the CPU may > be accounted between ktime_get_mono_fast_ns() calls. Disable preemption > explicitly in __csd_lock_wait(). This is a preparation for the next > patches. > > Signed-off-by: Chuyi Zhou > Acked-by: Muchun Song Reviewed-by: Steven Rostedt (Google) -- Steve > --- > kernel/smp.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/kernel/smp.c b/kernel/smp.c > index f349960f79ca..fc1f7a964616 100644 > --- a/kernel/smp.c > +++ b/kernel/smp.c > @@ -323,6 +323,8 @@ static void __csd_lock_wait(call_single_data_t *csd) > int bug_id = 0; > u64 ts0, ts1; > > + guard(preempt)(); > + > ts1 = ts0 = ktime_get_mono_fast_ns(); > for (;;) { > if (csd_lock_wait_toolong(csd, ts0, &ts1, &bug_id, &nmessages))