From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 7C3D6C3065C for ; Thu, 4 Jul 2024 06:04:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=iUZr96xMOSfv7Vj5yUshaHHzKxbkwsjS/SyK6oVOOqs=; b=I6LPpLEM4cUPoHIRFlFRmyfs/m 3HmeAyvtBle6MBHiy8jBGpSU+TaMJ2FjgroInktKAoZleu8fmCZMQkrxRS+jKLPI8x7vUGBWbcWvt w7ghxKAMkVUGVyWdk0hJxiWYmyZTkU6okg72AVUzSJNLojJb3WlZ10SpXPxuRxWRPcdaQpI+QSvY4 DbvqW43J2MX6HC2Aj2eXpAxBKs6TG+8ntyIZQ36zjaKj3IH4kGMlADGNueBqvNgsWIqOp84eMACLH I7R+MyL5PD/mtIf7MpnA5yH4nMZhsVc6QiI6bTt4tvowuvGQVY3SyUGSEnx0upResmHcY/Cf5du+7 /vOqt6Ig==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sPFZm-0000000CI0Z-32bF; Thu, 04 Jul 2024 06:04:14 +0000 Received: from smtp-out2.suse.de ([195.135.223.131]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sPFZh-0000000CHy1-1OWd for linux-nvme@lists.infradead.org; Thu, 04 Jul 2024 06:04:13 +0000 Received: from imap1.dmz-prg2.suse.org (unknown [10.150.64.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id CAB371F79B; Thu, 4 Jul 2024 06:04:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1720073047; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=iUZr96xMOSfv7Vj5yUshaHHzKxbkwsjS/SyK6oVOOqs=; b=Ujtu5344Vbej/SiIeN9bUEEXbu/pV52hhpbn10pxKV+xlwEQWrgIPK1eyVVRTNZf39VF7S mhxKZu58XLuecUVxWmrnR+vfN2jyir/IA2oEBK8l+gjFv+HqLHnAMOqF+aeu0PihcmEvfM nkgdr8VNN3SAyB7SGaIs9hiKgsA5FIQ= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1720073047; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=iUZr96xMOSfv7Vj5yUshaHHzKxbkwsjS/SyK6oVOOqs=; b=/w6/rq8dEenXIrdd/2pv8XzuzTkcNAkQaORNIsoUcTVTuTAM/tk60o4gpcMReUTjKXbkyu MTf8IQVFXof3nHCA== Authentication-Results: smtp-out2.suse.de; none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1720073047; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=iUZr96xMOSfv7Vj5yUshaHHzKxbkwsjS/SyK6oVOOqs=; b=Ujtu5344Vbej/SiIeN9bUEEXbu/pV52hhpbn10pxKV+xlwEQWrgIPK1eyVVRTNZf39VF7S mhxKZu58XLuecUVxWmrnR+vfN2jyir/IA2oEBK8l+gjFv+HqLHnAMOqF+aeu0PihcmEvfM nkgdr8VNN3SAyB7SGaIs9hiKgsA5FIQ= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1720073047; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=iUZr96xMOSfv7Vj5yUshaHHzKxbkwsjS/SyK6oVOOqs=; b=/w6/rq8dEenXIrdd/2pv8XzuzTkcNAkQaORNIsoUcTVTuTAM/tk60o4gpcMReUTjKXbkyu MTf8IQVFXof3nHCA== Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id 83E871369F; Thu, 4 Jul 2024 06:04:07 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id AGsAHlc7hmaCIAAAD6G6ig (envelope-from ); Thu, 04 Jul 2024 06:04:07 +0000 Message-ID: <2d2a27e2-4f73-48ae-9433-14c765c2b587@suse.de> Date: Thu, 4 Jul 2024 08:04:07 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 3/4] workqueue: introduce helper workqueue_unbound_affinity_scope() Content-Language: en-US To: Tejun Heo , Hannes Reinecke Cc: Sagi Grimberg , Christoph Hellwig , Keith Busch , linux-nvme@lists.infradead.org References: <20240703135021.34143-1-hare@kernel.org> <20240703135021.34143-4-hare@kernel.org> From: Hannes Reinecke In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Spamd-Result: default: False [-4.29 / 50.00]; BAYES_HAM(-3.00)[100.00%]; NEURAL_HAM_LONG(-1.00)[-1.000]; NEURAL_HAM_SHORT(-0.20)[-0.988]; MIME_GOOD(-0.10)[text/plain]; XM_UA_NO_VERSION(0.01)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; MIME_TRACE(0.00)[0:+]; TO_DN_SOME(0.00)[]; MID_RHS_MATCH_FROM(0.00)[]; ARC_NA(0.00)[]; RCVD_TLS_ALL(0.00)[]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; FUZZY_BLOCKED(0.00)[rspamd.com]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_FIVE(0.00)[6]; FROM_EQ_ENVFROM(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; RCVD_COUNT_TWO(0.00)[2]; DBL_BLOCKED_OPENRESOLVER(0.00)[imap1.dmz-prg2.suse.org:helo] X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240703_230409_551833_0920323F X-CRM114-Status: GOOD ( 17.51 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On 7/3/24 19:31, Tejun Heo wrote: > Hello, Hannes. > > On Wed, Jul 03, 2024 at 03:50:20PM +0200, Hannes Reinecke wrote: >> For drivers creating their own workqueue it might be useful to >> switch to the 'cpu' unbound affinity scope to keep the locality >> and reduce contention. As it's cumbersome to instruct the user >> how to switch to affinity scope from userland introduce a helper >> workqueue_unbound_affinity_scope() to let the driver set the >> affinity scope directly. > > So, there's already apply_workqueue_attrs() to change the unbound workqueue > attributes including affinity scope. It's cumbersome to use because the > attribute structure has to be allocated and then freed. The alloc/free is > for the cpumasks, so if the API is too cumbersome, maybe we can just make > the cpumask part optional? ie. Allow using workqueue_attrs without going > through alloc if cpumasks don't need to be modified. There probably should > be a function to read attrs from a workqueue too. > Sure; it would be ideal if one could allocate the attributes on stack, and then just call 'apply_workqueue_attrs()'. And if the attrs don't include a cpumask then just leave it unchanged. Let me see... Cheers, Hannes -- Dr. Hannes Reinecke Kernel Storage Architect hare@suse.de +49 911 74053 688 SUSE Software Solutions GmbH, Frankenstr. 146, 90461 Nürnberg HRB 36809 (AG Nürnberg), GF: I. Totev, A. McDonald, W. Knoblich