From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.223.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2FEB52FD1D0 for ; Wed, 3 Sep 2025 12:36:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.135.223.131 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756902998; cv=none; b=OQ7maw39UO4wm+BFnYzv2FWNfeL/N2Uf+El3lGQXt4gm2rCb2QKCAOy6HYhcmUy9sDfrKY+pITbMCcpap9C/rbI9zArFyVDmJUOfMkMK3y2begRZz2NTMY7P0u4gFayRIexcz0uYAIk4EdfEWVK5kFQyuPAfcxxxXG1FdwFeJto= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756902998; c=relaxed/simple; bh=l/WUmSKmcloVy0aJQRPVTdT7iDD8Xpxi1iTBHrSsDs0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=qKMh+rmMrUOzDvwFgwtdUTnVatiOBIidaR3Yffb9fAW5/YQfmmy4XE8+ZijH78WtP04MlFb5d+Zep0ol5v0pivanEjEJIncTu4LtIAI4tr8OY0sQQtIPhwOkdEnADgg5tV1O/rRNHvhjFbS/E6OWuWEwlce6YyhgXdQNA8jKCb0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de; spf=pass smtp.mailfrom=suse.de; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b=kVjoFdCg; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b=JC7gL9++; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b=kVjoFdCg; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b=JC7gL9++; arc=none smtp.client-ip=195.135.223.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b="kVjoFdCg"; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b="JC7gL9++"; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b="kVjoFdCg"; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b="JC7gL9++" Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [IPv6:2a07:de40:b281:104:10:150:64:97]) (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 53B3A1F453; Wed, 3 Sep 2025 12:36:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1756902994; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Z4dkn1xOtjZMvux09Ypde4SPog5LI5mjRt8sFdLaY4U=; b=kVjoFdCgu/5/fm2+jELu+JLMX4XJc08ulrCIWfDshl3SRtjuY50CbL41pdnlV1OKFRuenV FPAoq4yhQZqcXvNj3heuoiNr6bzpfxXstXbAkQ7u9kfZU81EfA4D+VFODrDuySMAohMReg zzO9RSlJ8LNx3dXJLq2V+Q8WFDVle98= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1756902994; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Z4dkn1xOtjZMvux09Ypde4SPog5LI5mjRt8sFdLaY4U=; b=JC7gL9++1ZpB9YCxnC/6M9nz3W8JxHmybvcmSdFTfEWWWDkcRfZCWClUCvdzzxdxrLUTIf yBSx//eaP2+gDMAA== Authentication-Results: smtp-out2.suse.de; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=kVjoFdCg; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=JC7gL9++ DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1756902994; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Z4dkn1xOtjZMvux09Ypde4SPog5LI5mjRt8sFdLaY4U=; b=kVjoFdCgu/5/fm2+jELu+JLMX4XJc08ulrCIWfDshl3SRtjuY50CbL41pdnlV1OKFRuenV FPAoq4yhQZqcXvNj3heuoiNr6bzpfxXstXbAkQ7u9kfZU81EfA4D+VFODrDuySMAohMReg zzO9RSlJ8LNx3dXJLq2V+Q8WFDVle98= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1756902994; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Z4dkn1xOtjZMvux09Ypde4SPog5LI5mjRt8sFdLaY4U=; b=JC7gL9++1ZpB9YCxnC/6M9nz3W8JxHmybvcmSdFTfEWWWDkcRfZCWClUCvdzzxdxrLUTIf yBSx//eaP2+gDMAA== 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 4149513A31; Wed, 3 Sep 2025 12:36:34 +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 XMvsD1I2uGj2MAAAD6G6ig (envelope-from ); Wed, 03 Sep 2025 12:36:34 +0000 Date: Wed, 3 Sep 2025 14:36:33 +0200 From: Daniel Wagner To: Hannes Reinecke Cc: Daniel Wagner , Jens Axboe , Keith Busch , Christoph Hellwig , Sagi Grimberg , "Michael S. Tsirkin" , Aaron Tomlin , "Martin K. Petersen" , Thomas Gleixner , Costa Shulyupin , Juri Lelli , Valentin Schneider , Waiman Long , Ming Lei , Frederic Weisbecker , Mel Gorman , Mathieu Desnoyers , linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-nvme@lists.infradead.org, megaraidlinux.pdl@broadcom.com, linux-scsi@vger.kernel.org, storagedev@microchip.com, virtualization@lists.linux.dev, GR-QLogic-Storage-Upstream@marvell.com Subject: Re: [PATCH v7 01/10] lib/group_cpus: Add group_masks_cpus_evenly() Message-ID: <5397286b-bb1f-493b-9d7d-b4168a67efe6@flourine.local> References: <20250702-isolcpus-io-queues-v7-0-557aa7eacce4@kernel.org> <20250702-isolcpus-io-queues-v7-1-557aa7eacce4@kernel.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-Spamd-Result: default: False [-4.51 / 50.00]; BAYES_HAM(-3.00)[99.99%]; NEURAL_HAM_LONG(-1.00)[-1.000]; R_DKIM_ALLOW(-0.20)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; MX_GOOD(-0.01)[]; ARC_NA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; MISSING_XM_UA(0.00)[]; RCPT_COUNT_TWELVE(0.00)[26]; MIME_TRACE(0.00)[0:+]; TO_DN_SOME(0.00)[]; FUZZY_RATELIMITED(0.00)[rspamd.com]; RCVD_TLS_ALL(0.00)[]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; FROM_EQ_ENVFROM(0.00)[]; FROM_HAS_DN(0.00)[]; R_RATELIMIT(0.00)[to_ip_from(RL71uuc3g3e76oxfn4mu5aogan)]; RCVD_COUNT_TWO(0.00)[2]; TO_MATCH_ENVRCPT_ALL(0.00)[]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.de:dkim]; DKIM_TRACE(0.00)[suse.de:+] X-Spam-Flag: NO X-Spam-Level: X-Rspamd-Queue-Id: 53B3A1F453 X-Rspamd-Server: rspamd2.dmz-prg2.suse.org X-Rspamd-Action: no action X-Spam-Score: -4.51 On Thu, Jul 03, 2025 at 08:18:50AM +0200, Hannes Reinecke wrote: > > +/** > > + * group_mask_cpus_evenly - Group all CPUs evenly per NUMA/CPU locality > > + * @numgrps: number of groups > > + * @cpu_mask: CPU to consider for the grouping > > + * @nummasks: number of initialized cpusmasks > > + * > > + * Return: cpumask array if successful, NULL otherwise. And each element > > + * includes CPUs assigned to this group. > > + * > > + * Try to put close CPUs from viewpoint of CPU and NUMA locality into > > + * same group. Allocate present CPUs on these groups evenly. > > + */ > > Description could be improved. Point is that you do not do any > calculation here, you just call __group_cpus_evenly() with > a different mask. I updated the documentation, it matches with group_cpus_evenly but with the constrain mask.