From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (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 9ED7A20FABC for ; Wed, 22 Jan 2025 18:17:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737569825; cv=none; b=DTzV4AEp5Z/7Ohyidr6Bew3OgA6cEH/MdD27qZLEt8G68fFtQFJkZXaq7pYJkTeu2noi4aet9qZdfUH0vFM2Pey1EvUBpRCpnfT80wauTcSniNEoh61QDYX2804RKEqOImB/rZejwS+vj+HR51VGv9OmQEq4tMtK68hqYhDgPXc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737569825; c=relaxed/simple; bh=xd/cWCKnCzABygKxOGD6w5jfbHsdhZu5hxpwb1ssplo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=WQkIMM6CpK6iI3LMsuBQIAIH6v65fgDcaJA+NXz9/FMgmyaADmAEWVXmEkcZRg6EKe7Y8T0BguVbGCP5vJVtWooy79SGP2Piob86KezjqGhe13EwUW/ctjEfjwizT5tVz7c+jOYU8JYOdj3TMUUc+j3NhjumGc1m82v7b24LHL8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=fabHMtdd; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="fabHMtdd" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=xd/cWCKnCzABygKxOGD6w5jfbHsdhZu5hxpwb1ssplo=; b=fabHMtdd9iq0/VH9VyCFV/WfUt IjebdqrC3+Zqeb/LsPERSqgUgVDk8t5gVagbGCk9IaRsuWOp90nOEh2zEnFKmPrUUAXmO9YxJXTSb 93ueV5PpNiYt2uHX32nxwtN45DY5r1wt3/KXG/KSrNwjXq44GbCPBicU3zqohQ8tEZZHn/u4WEGgQ Xu4Nax5Gltcapmv4RON2aRqVX7t5snDkpr8gKr2n/+0m1OGlm8cO8gZeONyinBqYBrtYZU8xL5gu8 16xjwwm3UD89QM/crxzS/o99DmT3SRutj/OI55h6qw4h/BnR2maI1LlShmlSRbW26IIGDPd27Z8t7 xRNKar0Q==; Received: from 77-249-17-89.cable.dynamic.v4.ziggo.nl ([77.249.17.89] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.98 #2 (Red Hat Linux)) id 1tafHg-00000005cCS-0UEy; Wed, 22 Jan 2025 18:17:01 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 6BE9B300677; Wed, 22 Jan 2025 19:16:59 +0100 (CET) Date: Wed, 22 Jan 2025 19:16:59 +0100 From: Peter Zijlstra To: Waiman Long Cc: Ingo Molnar , Will Deacon , Boqun Feng , linux-kernel@vger.kernel.org Subject: Re: [PATCH] locking/semaphore: Use wake_q to wake up processes outside lock critical section Message-ID: <20250122181659.GB34562@noisy.programming.kicks-ass.net> References: <20250122011314.2869715-1-longman@redhat.com> <20250122103914.GI7145@noisy.programming.kicks-ass.net> <414a685b-5a30-4792-b01d-35e8099d965b@redhat.com> 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-Disposition: inline In-Reply-To: <414a685b-5a30-4792-b01d-35e8099d965b@redhat.com> On Wed, Jan 22, 2025 at 09:51:04AM -0500, Waiman Long wrote: > Anyway, do you think this patch is worth taking? There are may be other > cases like this that are hiding somewhere and showing up from time to time. No objection to the patch, we've been moving wakeup out from under the lock locks for a while now. It just needs a new rationale, since the changelog is a bit iffy as-is.