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 DA2F84315A; Mon, 11 Aug 2025 17:08:28 +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=1754932109; cv=none; b=bNehGSGUa4EZ20PsuVE2G6CvyLHfIXw+p7ntuepTrihU5A5yJhDxU+5k8zjk/EVxS3NbSOFJvYGJ+6yGhxjO6h9t/ahyfFUfDeKyWMsChevAdBdgINjozDbcbrH/y/yvyrsERrJEc6uf14CCxwmiTUvK8X3fC5LuqwkDRJFup0o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754932109; c=relaxed/simple; bh=Cfd4uOaakFu71BLj4bWH0zH9dw3qu+n89q2tGbiG6Wo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=j3cMXWnYYmtvUFA3Ckcg8yK4fh7D3RGjJqZkXSKyhoFofg/Ly4Am2grcBJthlAAPgSJ2wNToOH6KkYO/ynj9hCwaGAnSVhpe0oe/F10inG+pZjMkoXbb/RdVHGrdpHw7yi/GRWUGDEZIgp2fqCkjnwWQ+wYZNSjdvDKlleSJFdk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=kUQPHby5; 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="kUQPHby5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3B0DFC4CEED; Mon, 11 Aug 2025 17:08:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1754932108; bh=Cfd4uOaakFu71BLj4bWH0zH9dw3qu+n89q2tGbiG6Wo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=kUQPHby5gwLeLdKNjaHFpxSBJTx9Qo4yq/kqG7Wa/D6ITBUGGEYn2nf3Y6tLy3Cg8 qhEmwbRsio3lAnI/vczf8hLyPqh1GK5bwlEBH9f4BSg9FEuc0aSzQDH9qBKhnBD93T Uhx0aLRTjsoLV6PwwEQWCHaTuFDxRwSoCLre4iE35JoSv7bjSSsFVug/CAYq+PDxci sBvqNXa1PN37yE+uw7MsGf0XJxmv09GWIof2TeS4UCiNaKTBkPhw6kuMU18Q2r2bAa X6pFI0rMWidPriqi9qVytuu1fbBGFoZs5+SAl/cHsN2r8xDUakspbfgXHzfhqooW1N 0DYB1RV/aS8Ig== Date: Mon, 11 Aug 2025 07:08:27 -1000 From: Tejun Heo To: Christian Loehle Cc: arighi@nvidia.com, void@manifault.com, linux-kernel@vger.kernel.org, sched-ext@lists.linux.dev, changwoo@igalia.com, hodgesd@meta.com, mingo@redhat.com, peterz@infradead.org Subject: Re: [PATCH v3 2/3] sched_ext: Provide scx_bpf_task_acquire_remote_curr() Message-ID: References: <20250805111036.130121-1-christian.loehle@arm.com> <20250805111036.130121-3-christian.loehle@arm.com> Precedence: bulk X-Mailing-List: sched-ext@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Sat, Aug 09, 2025 at 09:01:18AM -1000, Tejun Heo wrote: > On Tue, Aug 05, 2025 at 12:10:35PM +0100, Christian Loehle wrote: > > Provide scx_bpf_task_acquire_remote_curr() as a way for scx schedulers > > to check the curr task of a remote rq without assuming its lock is > > held. > > > > Many scx schedulers make use of scx_bpf_cpu_rq() to check a remote curr > > (e.g. to see if it should be preempted). This is problematic because > > scx_bpf_cpu_rq() provides access to all fields of struct rq, most of > > which aren't safe to use without holding the associated rq lock. > > > > Signed-off-by: Christian Loehle > > Applied 1-2 to sched_ext/for-6.17-fixes. Reverted due to compatibility issues. Let's try again with warnings as discussed in the other subthread. Thanks. -- tejun