From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from fanzine2.igalia.com (fanzine2.igalia.com [213.97.179.56]) (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 B768A194A6C; Tue, 18 Aug 2026 14:16:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.97.179.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787062581; cv=none; b=Kofxo0Vmuxxd3dpMgF8XSPMDFWmLrrHoCk8w07uW3S97aT7nhYTo/YtZ0mEWQsuxqKQ6bpBKKcjoqvI79UrJEwq0CoSeipoWKE8F2ma/PrgifuLSaAxRFI/SBZw8ca+evj3qaVdrovA8SYfroedgbd9TCbvAjUH+3+hc0AHw8MI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787062581; c=relaxed/simple; bh=8u0oCn+NiSuV+rYi0lA1lQCTq5qZsCZdVncaYbEYCbc=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=KSTKoUlHraldHzymv7iSkunynUbGiSv+2eAA9BjNMfUts7Y0yuPvit1NNf6gIEKFo3Eb3b+0zNTfQX1XR2tuhEJd2imTgyL4ECo0veqyrVwQtIknUecup1Y/VuJOMPZVZeJwz3QypLXXS2PJEBGqFAUTV5GAz1kzwiq2yMz7138= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com; spf=pass smtp.mailfrom=igalia.com; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b=Jh5WO0a8; arc=none smtp.client-ip=213.97.179.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=igalia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b="Jh5WO0a8" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:Content-Type:From:Cc:To:Subject: MIME-Version:Date:Message-ID:From:Reply-To; bh=7tAq3rCowBXZ9SwgwYlVliEHJMSYCq4wJjeOTJnXxmM=; b=Jh5WO0a8ykWP8fdS8llEUufyVP p9AYgbp4feKpsazNsOHTyepHsW3yfRFVo9mzJ0pPm+Ph6jH4PPwWBiEtFrCyYdlWKp1owKn5A8RYG iZgEjoH/86srUXfNAoccgpa+y5mq3djHiyzXNwmitEc23EcCXsAray1wXWUWPYeLEaQ73SqqvDMon apd/cIbRA7MQ2uD6iUHymILwbCHXRb8O7Q8Zs+kVcEGpEH7K21AjuVdrbZn213nJjAjiyAeS7d07+ 5YqTah8cbKCUHVRUsIILZELqUrryjQPN8QxsprI/JBNnNPczkmNnU9HKqTSuF8Lsyu1rcP30xBovK NYXjYm2g==; Received: from [58.29.145.179] (helo=[192.168.8.203]) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_128_GCM:128) (Exim) id 1wwKbm-005eOT-41; Tue, 18 Aug 2026 16:16:06 +0200 Message-ID: <2f65d156-07ad-40aa-9ae1-2e14f836cf69@igalia.com> Date: Tue, 18 Aug 2026 23:15:59 +0900 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] sched_ext: allow ops.cgroup_set_bandwidth() to be sleepable To: Tejun Heo Cc: void@manifault.com, arighi@nvidia.com, emil@etsalapatis.com, kernel-dev@igalia.com, sched-ext@lists.linux.dev, linux-kernel@vger.kernel.org References: <20260817170941.668571-1-changwoo@igalia.com> <9ffe41fba1d0462a27443e95c5e3e03b@kernel.org> From: Changwoo Min Content-Language: en-US, ko-KR, en-US-large, ko In-Reply-To: <9ffe41fba1d0462a27443e95c5e3e03b@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Hello, On 8/18/26 2:53 AM, Tejun Heo wrote: > Hello, > > On Tue, Aug 18, 2026 at 02:09:41AM +0900, Changwoo Min wrote: >> +/* >> + * Capability marker for userspace. The sleepable allowance for >> + * ops.cgroup_set_bandwidth() (see bpf_scx_check_member()) is a verifier >> + * property with no other symbol a scheduler can probe, so this no-op function >> + * exists solely so its presence in the kernel's BTF can be detected. It has no >> + * callers; __used keeps it from being optimized away. >> + */ >> +__used void scx_cgroup_set_bandwidth_may_sleep(void) {} > > __used only prevents the compiler from dropping the function. With > CONFIG_LD_DEAD_CODE_DATA_ELIMINATION, the linker can still garbage > collect its section, so please add __retain too (cf. __bpf_kfunc). > > Also, we'll likely accumulate more of these markers over time, so let's > give them a shared prefix - scx_compat_marker_ or something like that - > and collect them in one place, maybe towards the end of ext.c next to > the module init code. Thanks for the comments. I will address these two and send v2 shortly. Regarding the sashiko review, I think that needs to be addressed separately. Regards, Changwoo Min