From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from stravinsky.debian.org (stravinsky.debian.org [82.195.75.108]) (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 1CCA83B47E6 for ; Thu, 25 Jun 2026 16:51:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=82.195.75.108 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782406317; cv=none; b=txfS3KINBxGBpBkOPZnmswoy8wsZ/8oRqzJLA+NgJEYtKJlDpKo9evu4a6GqIhq8qklMz1jbZDXL7w43PwBi+tmRCdxbsM0JyjIHKxrpgqJl8s3QzSyxJvS3r8BE2XJjbqUBArvp+UFgPKS3YnYra2ItP498oRV3Y3CDBGa0dPI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782406317; c=relaxed/simple; bh=ySXaYe/Cgd9LYB5mlz8qhrPVOM1mXh9+cI7ONPMvdPM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=SDyAT0SURxl804b/OzhzsAQGEHbFQ794chj7jyluARLFrwQI4UxhrEFRCcmjuhmcmYGbk/4dhZ0nT1Rg0NnhX07+eP0aK/M5zj87zBmMfWZS7Sg2K3HfpymmQHBMMuDO1FSaznUkVLG6tGKHC0tzrlUzv8j6ixDOitC7h1Na24U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=debian.org; spf=pass smtp.mailfrom=debian.org; dkim=pass (2048-bit key) header.d=debian.org header.i=@debian.org header.b=X/qZbxOv; arc=none smtp.client-ip=82.195.75.108 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=debian.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=debian.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=debian.org header.i=@debian.org header.b="X/qZbxOv" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=debian.org; s=smtpauto.stravinsky; h=X-Debian-User:In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=TdXfp08zlCM6P2Bx8l++stABKOWTU9ES92D9HuhMMf0=; b=X/qZbxOvWgtQtZgvYW2z+e0bmh y9dj0mYEc8xU+Ey7Ly6fAWUfb4kdKydV8zp9Iw3cahAdxbmQeB50VC2ELlxP41a12oL2cnNWFJBB+ p4Uh5Iuy5AN5KTPUxeSePMV8u/QUcPUDPMoC97qLrSihqJQ1ZmWQBpe3/6GAEVjn5rg8GDN7pXaaa XhMzeSAIGiKkrDsRZfVl2t/wfm6OgppAgIZIHmUMcPdfewTN267pRbNUOFJvJZbhWTcHuucd1Hjbq H97M+Ijaknc1eTofHKmxRUemVy4sqG+4dHTFV+OWObE4vUmhNjnWmwLC2rvm9yNEAhrhvmOtt/clT ZNMCCJNA==; Received: from authenticated-user by stravinsky.debian.org with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.96) (envelope-from ) id 1wcnIq-003L8e-1Y; Thu, 25 Jun 2026 16:51:48 +0000 Date: Thu, 25 Jun 2026 09:51:43 -0700 From: Breno Leitao To: Tejun Heo Cc: Lai Jiangshan , bigeasy@linutronix.de, linux-kernel@vger.kernel.org, marco.crivellari@suse.com, frederic@kernel.org, Hillf Danton , kernel-team@meta.com, kmagar@redhat.com, psuriset@redhat.com, david.dai@linux.dev Subject: Re: [PATCH v4 1/3] workqueue: split kick_pool() into kick_pool_pick() + wake_up_q() Message-ID: References: <20260624-fastwake-v4-0-7b6d7b494a44@debian.org> <20260624-fastwake-v4-1-7b6d7b494a44@debian.org> 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: X-Debian-User: leitao On Wed, Jun 24, 2026 at 08:46:59AM -1000, Tejun Heo wrote: > On Wed, Jun 24, 2026 at 04:47:39AM -0700, Breno Leitao wrote: > > + wake_q_add(wakeq, p); > > This is two extra atomic ops for every work item scheduling. This isn't > necessarily a deal braker but is this the only way to do this? > > Can't you just stash the task pointer, extend irq disabled region and wake under rcu > protection? Agreed, that's a better approach. Thanks for the suggestion. I have a working PoC implementing this. I'll clean it up and post an updated series. Thanks, --breno