From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 2208B221F21 for ; Fri, 7 Mar 2025 15:58:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741363129; cv=none; b=Z6JCEQ16jACviw4GawlJN9X32LVv0YM84AQfKPfpUbWRUwOfC7xnRXBi+pLD4h7NHbmKFzKGwNBILGlSIGW8dwVllCN9VehDfaSDVY0YzBlHUXO6QpSSZvI7LedWvQA9PPDi0dcZ1JmDajxoUNdK/RWirzYDKXHFoE3le3Z/UOw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741363129; c=relaxed/simple; bh=fH/5vaAn2+rupV0lSUMQO+zbP+VjO2bOTmV9omTmFak=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=qjsiF7MD/P4DycFo/x38dgQq05h987HpVx0XFOFo5A0G5mdSdZZ0ryLqHRcgJKcq1SmncJ8NDF1lhhOVHLU63m7F22Ab1mSEqp+Ih2d+sIhv3IzNPK98NM0OYJ6tV5k2wKUD1k5YlH6dNDFvZrs07cvRoOfbAOj5P9rU8cutQgo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VF+sU4Rs; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="VF+sU4Rs" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 773BEC4CEE7; Fri, 7 Mar 2025 15:58:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1741363128; bh=fH/5vaAn2+rupV0lSUMQO+zbP+VjO2bOTmV9omTmFak=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=VF+sU4RsKeo4es9ZCUyEy8Z3VxN/hV+NqpiMdVD9DwhVPdYvsVZTSBrociDmtpgCf 1F+4exBazlf9Ox7D40fzJ2sKjlXni83K1oK+/5gp+N6Hxohq7Ro6dSK420UXNRv//g OMQNiuQSjqjCEJshATztaRZdoigll1EwxBLmxssssIQkHPNSunHvYCXf2yRgm0QBMo iJZ0QL0Ge1ni0abQUevf0lyzxNcSlNcyCJ1dmZ2Ax0ZrMto3S2xHlWl7+Fdy12X2AN JxrGKeMYvozP2JBGx3vYJZ01u7GmYJR7w7bG0Hr5agHhaw2vQ+XVGCLObdDb9BBKdv y4vQXYC2NABGg== Date: Fri, 7 Mar 2025 05:58:47 -1000 From: Tejun Heo To: lirongqing Cc: void@manifault.com, arighi@nvidia.com, changwoo@igalia.com, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH] sched_ext: Simplify cpumask computation in balance_scx Message-ID: References: <20250307064533.2663-1-lirongqing@baidu.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: <20250307064533.2663-1-lirongqing@baidu.com> On Fri, Mar 07, 2025 at 02:45:33PM +0800, lirongqing wrote: > From: Li RongQing > > Compare SMT CPU against RQ CPU and skip balance it, to avoid calling > for_each_cpu_andnot() and cpumask_of(), they are relatively expensive How is cpumask_of() expensive? I have a hard time seeing how this would actually improve anything. Do you have any measurements? Thanks. -- tejun