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 3AF8626868F for ; Wed, 23 Apr 2025 23:46:00 +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=1745451961; cv=none; b=ggP+1puXSvuFreBMACPhD+LVrR1A9/pkJ05aI45KArLnUmVEzMljFa9OVB4clAHTlH+HjsllLZVfzMqmASkUhYE55LyFzs43H58BZBqHIJBD/QRXaUOADPWXSIR3HQNNFvRWnWKDcCYXDmOUkeB5bD6Ixctj/0BIm84jI8AFVe4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745451961; c=relaxed/simple; bh=uCC9DO68y8+JlmMQrcLGfGpDqTbOtuWORndFoJjnp4g=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=e0sa69LQ+xh/wp1P3hoQx2muLQhGnCq4XrRfwmyKTQBlLDEj4W10qjkon9ScqDgzPDoHFWRY/GjSTVOAk/wGUgmAincVmv69UpM18cEN3fd6MTi97E8C8h0DMyVXqDRxGX370mo76hlyxw9yT7AXGWzet+NqU52Rw30smNIPyik= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=pWqPN1a0; 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="pWqPN1a0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8FC20C4CEE2; Wed, 23 Apr 2025 23:46:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1745451960; bh=uCC9DO68y8+JlmMQrcLGfGpDqTbOtuWORndFoJjnp4g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pWqPN1a047cwQ6i7KmI8Hxv81Z2JBAAlEUxUAVLPLi2C4S/csw31ObVDhspujMrIO mJHVK0xsONalY7IuCwUb534VXQ7UtvL05kQvuMuvGZPfPjPeuXqod0ZIVTz1jgaCEr Y8iZLFjdIk7RUw9lliQnj6qo/X+EnghnEhYtiejFOSJ1OeKmsUE5/fYzDOaPzaQbNj AIcvlHU7c1KGHUDuRkYbC1zBUpqfXpqaitE9A0NaHzeC8ulHFzhYRaUCA1hMXBrVdE K0tlEk66Wi1WITFxWi9RQODVHYRpFpWW3b10lderWOlR2QRReEUtJa17nALgNHY0Rl iO8FcWJIVVOQg== From: Tejun Heo To: David Vernet , Andrea Righi , Changwoo Min , linux-kernel@vger.kernel.org Cc: Tejun Heo Subject: [PATCH 12/12] sched_ext: Clean up SCX_EXIT_NONE handling in scx_disable_workfn() Date: Wed, 23 Apr 2025 13:44:50 -1000 Message-ID: <20250423234542.1890867-13-tj@kernel.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250423234542.1890867-1-tj@kernel.org> References: <20250423234542.1890867-1-tj@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit With the global states and disable machinery moved into scx_sched, scx_disable_workfn() can only be scheduled and run for the specific scheduler instance. This makes it impossible for scx_disable_workfn() to see SCX_EXIT_NONE. Turn that condition into WARN_ON_ONCE(). Signed-off-by: Tejun Heo --- kernel/sched/ext.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c index d27193010b6a..d963aa5c99e1 100644 --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -4749,13 +4749,9 @@ static void scx_disable_workfn(struct kthread_work *work) kind = atomic_read(&sch->exit_kind); while (true) { - /* - * NONE indicates that a new scx_ops has been registered since - * disable was scheduled - don't kill the new ops. DONE - * indicates that the ops has already been disabled. - */ - if (kind == SCX_EXIT_NONE || kind == SCX_EXIT_DONE) + if (kind == SCX_EXIT_DONE) /* already disabled? */ return; + WARN_ON_ONCE(kind == SCX_EXIT_NONE); if (atomic_try_cmpxchg(&sch->exit_kind, &kind, SCX_EXIT_DONE)) break; } -- 2.49.0