From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793718072; b=s6NJJAChjJh4AUqAX4UKK5vjnGFSEIvg86Q88ouwgimCiSbqhIOyvkSWk0ah/EaWEl3z gzMQZZb6EsXepoYuZlmi/W+aknzl3yzBNFy6Ss5ICCNZugUyBiBXJ7CKT6kGWBPYFrX9p E4h/vKz42/2Eq6wCzArpcCzmYRUnHxKJlBeL62+zr0Y3S/PxIRfKimI8t4wlFuXWFbhQA G/g6II/UWw46t7cE5CsJBwuhB/y7cawkmhVqzU/Q/RkdNryO+Y1hxN6O4y6JcgeRaD7/b oKIak6bdo0Tqzn5GECXVfF8SVHz6j2EqAepXs8mlK/b/TTMBq2i3f5Dv8oRQ3s3cxag== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793718072; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: References:MIME-Version:Content-Type:Content-Disposition: Content-Transfer-Encoding:In-Reply-To; bh=YIDXQ4LW50kfGoDD/n5YI6WPW7QshVZmOorzzd9ZaKM=; b=PznIMPBWUQ9bSOp1Jo6ZeD3eOx9C29ZaJ8xrFxOYckpDQWwLamzRUQdCOHUi17nDC+WV ywpqgDHmy0yghpBpKueXS32a0m+jABRNCrWg+VXUFSVf4g+gk72O302ox826Qw4zSm4vb T2zv6knIeDAFkE6T7NU2G7t3kxRF4WeoRshXig8OG2M8SvvxtE6+VtAcObZ/f7HjpkY0Q WNDNEkvnH4qEARCsO4hDXLNjsNbpMJu/eFql4dn2uRvh85USkuKDEH8qtouOLoMDb2smj DUxBT2MzmHWgAyNbzFDYud/P7vCvWAGRhbYH1DWgYBXmxE2gLZUxREBBWVetOJO4VeQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=ODbmtctK; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8CCA7606F61E for ; Tue, 3 Nov 2026 15:01:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=ODbmtctK Received: by smtp.kernel.org (Postfix) with ESMTPSA id CCF481F000C1; Tue, 3 Nov 2026 15:01:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793718072; bh=YIDXQ4LW50kfGoDD/n5YI6WPW7QshVZmOorzzd9ZaKM=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=ODbmtctK6ey4ItCUCWFbeMZSE56D99tTlV1QUMaYA/i1RQej0tUEqcOvef5XhpwWR XB+mVN2GfQAyp1bpS9F8X79nwmsmMFqY/MuTJ/cdLXmMpmGpwhMJ4tctDHfXAPENUE rE9TEgnW1tH/70PGGHLE6AXo57XJ9TRuGP+EddEfB/y3IK9OCyYpCUc8L0v1+yuFbR vxD7+Jdw01ELtZutGhJAGOrCjvkgbTRDHQeGaTcCt7egjp6KhHDFZFN7V2LJgDqVnO br5kEsp4Covrn8gKtTdn1lwK8UC8sj087mjLzzIfJoU8dmvN3Rol2OKWl0zR8EkxVD K4PVjHJ6PXAow== Date: Tue, 3 Nov 2026 16:01:08 +0100 From: Frederic Weisbecker To: Avi Weiss Cc: Anna-Maria Behnsen , Thomas Gleixner , Marcelo Tosatti , linux-kernel@vger.kernel.org Subject: Re: [PATCH] hrtimer: Retrigger local timers after clock changes Message-ID: References: <20261101141552.644764-2-thnkslprpt@gmail.com> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20261101141552.644764-2-thnkslprpt@gmail.com> Le Sun, Nov 01, 2026 at 04:15:53PM +0200, Avi Weiss a écrit : > clock_was_set() selects CPUs whose hrtimer deadlines move earlier > after a clock change. smp_call_function_many() excludes the calling > CPU even when it is in the mask, leaving its clock event programmed > for the old deadline. An overdue realtime timer can then expire > only when a later event triggers timer handling. > > Use on_each_cpu_mask() to retrigger the local CPU when selected, > without interrupting CPUs with unaffected deadlines. > > Fixes: 81d741d3460c ("hrtimer: Avoid unnecessary SMP function calls in clock_was_set()") > Signed-off-by: Avi Weiss > --- > kernel/time/hrtimer.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c > index 17dd38a6cee7..3133d7403a74 100644 > --- a/kernel/time/hrtimer.c > +++ b/kernel/time/hrtimer.c > @@ -1000,7 +1000,7 @@ void clock_was_set(unsigned int bases) > cpumask_set_cpu(cpu, mask); > } > scoped_guard(preempt) > - smp_call_function_many(mask, retrigger_next_event, NULL, > 1); Heh, this API is so error prone... If it really doesn't want to call on the local CPU (for some undescribed reason), it should at least be renamed to smp_call_function_many_butself(). > + on_each_cpu_mask(mask, retrigger_next_event, NULL, 1); Reviewed-by: Frederic Weisbecker -- Frederic Weisbecker SUSE Labs