From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) (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 ABAAE369214; Wed, 7 Jan 2026 16:19:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.40.44.10 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767802761; cv=none; b=cxiVm6EoLYXsUNGrf04y3SpUjFwTREMSU0vVLrR/Xcq8E63CEmEEBvVrhfonFzWw04Dz1Kc/o1Oi8qf0D8orQPUe9l3lCAc1KkONVxo0gxxNiia5Tu7boyNXehjmyNevnfpc2mAcmcMKeBMg+sDUnvHlOoINqgAL61vqYaDv8FI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767802761; c=relaxed/simple; bh=h4g1T8+nTdGRiKEX2zWnm5RgnG79J06XV+19EmwzTxw=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=lhkgdsh9gbi3kx2G3/xj91rfipU3sO+DJeBcFtXGfJCa/FYNgTeiZ90TW/VyWfanieXQBT3anM9y7sLDj0MUosXxAhPh0yoQqa4uBvZ7jJD4HeZUrb6I1zy0gFkWvFSUKdAjmAmb7iUl+bX34gBmrmcbOUmeO+OTGhezdiI1ePw= 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=216.40.44.10 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 omf05.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 4E792160476; Wed, 7 Jan 2026 16:19:11 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: rostedt@goodmis.org) by omf05.hostedemail.com (Postfix) with ESMTPA id 37D5E20018; Wed, 7 Jan 2026 16:19:09 +0000 (UTC) Date: Wed, 7 Jan 2026 11:19:35 -0500 From: Steven Rostedt To: Petr Tesarik Cc: Masami Hiramatsu , Mathieu Desnoyers , Sebastian Andrzej Siewior , Clark Williams , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-rt-devel@lists.linux.dev Subject: Re: [PATCH] ring-buffer: Use a housekeeping CPU to wake up waiters Message-ID: <20260107111935.3befc296@gandalf.local.home> In-Reply-To: <20260107111709.0d115cd8@gandalf.local.home> References: <20260106091039.2012108-1-ptesarik@suse.com> <20260106170405.425f469e@gandalf.local.home> <20260107085009.58fcffd4@mordecai> <20260107105137.4cf9a67e@mordecai> <20260107111709.0d115cd8@gandalf.local.home> 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: regmgp5xptze837exf5tromfaembwfp4 X-Rspamd-Server: rspamout04 X-Rspamd-Queue-Id: 37D5E20018 X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX19t1uYnw622G91V7nQiZPO3aimEGwqxAoA= X-HE-Tag: 1767802749-236976 X-HE-Meta: U2FsdGVkX18/wIi3/OMgHpXPjGUWt6PrTQOjaOrUDU49HogZnJHHwu/Vm2eb5nYUPuBswgrudCYbFK+vo10c6w2pMHNJK7/+WEwVvkSJLf36+FPI+RKB5AeZs3FpGCNIcOToiqYvHRHb/k7FvXEfvEDrt0NvqhLbvBPL5fFjsbXWDmBQRidwfZBOlSHDVKrA1pJsRzRUp8MEsOTMheAINzSHEBq2dNsj6GomR4KOCjB8KVbaVPcI8+lAbquE3f4FbbNhpGEwykX3OtF5Dg06cxsRGeGWaIingNANJERPMnRvvG++Q/TODzxbQxRTgQS7kPoY4qTrURw3ZSW6Yp+BsVsOPExFFjcH3LJC1NYS8UNcsN8pPOCfRLvzdocTvn7G On Wed, 7 Jan 2026 11:17:09 -0500 Steven Rostedt wrote: > Or we simply change it to: > > static inline void Actually, the above should be noinline, as it's in a slower path, and should not be adding logic into the cache of the fast path. -- Steve > rb_irq_work_queue(struct rb_irq_work *irq_work) > { > int cpu; > > /* irq_work_queue_on() is not allowed in NMI context */ > if (in_nmi()) { > irq_work_queue(&irq_work->work, cpu); > return; > } > > cpu = housekeeping_any_cpu(HK_TYPE_KERNEL_NOISE); > /* > * If CPU isolation is not active, cpu is always the current > * CPU, and the following is equivallent to irq_work_queue(). > */ > irq_work_queue_on(&irq_work->work, cpu); > }