From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792784152; b=hba/xUCKV+YfnzeFXmuEZjW+6bgojiXLXSLk8hkZLnR5LeJHJTsZ4wtVehSJayL2wZ2Q QWGykwhc1m5wu3tJ7zwZZzzEyfGGMyGQhUGubB+3k8vD/RM5uh1vw84bglyLcosK5N3nr 100mubQrK6LRNdcVC7BnlL54z1+Y7b9PjgW6ppU5mkUxIcABI1OhpZNXNToE6BGnSH7DU XywU4omEHib4iLIR3vRRdvRgHq+xweL41fM5/Ytv3CK+Ao/ZXGuQuSZBcJBUMogALm2dB cJabD+DYIy5JnwZ5gUMIeayCBLCvemWNvI+c8iL2sMsTU4cGxcfteNoqluAhNRo9+vA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792784152; h=Received:DKIM-Signature:Date:Message-ID:From:To:Cc:Subject: In-Reply-To:References:MIME-Version:Content-Type: Content-Transfer-Encoding; bh=X/K/xlMU8VWsC9nqOTbUQAuFMVle3BpL/szm2o/O0q8=; b=w5fZ3JWgU2Hq8mXfuOGQkAkycdEWapi1AEiVik2rI9hcOjRrn2rYcTVj4hKsASSq5yAw tPTWBn4D/9k+tKZLOcDc2rOOLeqlJob2Fg2qeBGy5d+BOiDdq9SzIkyxYnIpOzrLCpc1Z GPgMDSOwRTmJldQCWyXYWBaUpx80uTch02hoeLKhpEYN+BmGe2upnGjWznKjDMYthORga rgUILQlTLdR9COfHq2p78gXm8mhWsuI2ik/WZHlQwOaOO3rEPV2+Zw/KyfSUeYXbAFpdw A2uQzKy1H/6//zWXNkYY+5xNM7rUW2CaekV4FNvAeRkc5OcTRpz6AX/zr+vq1wc7YDA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=HeGD9YgC; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4C913606A31F; Fri, 23 Oct 2026 19:35:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=HeGD9YgC Received: by smtp.kernel.org (Postfix) with ESMTPSA id AEDF51F01828; Fri, 23 Oct 2026 19:35:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792784151; bh=X/K/xlMU8VWsC9nqOTbUQAuFMVle3BpL/szm2o/O0q8=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=HeGD9YgCJhvz+f30AkaO/mHFQZY+NnL6zPHkNEn7UblSTl8csBDZ99L3rSVNLT4Gx o47Ik2I+TEPMsI8Q6hBjUu2KXKMqsI2FtpTx8XEsZH4DE7E25CprfeC9r47SADKCTi cXt2yIokFtK1VIKVjvNRDtSOy2r9hUGm0SUE+MbbN9DZR8P198/Dd70MeSd5Wk6JLh C9ewYE2jFSQkG/ORgPl2d7Hy/YpDtZZPH3fZGFDXv7kRkGCEQfkgrEGq4WhRpmxsdn BlgmaFRNzsuUqJ7VXPIoXAeJgQayXHeQFJGWHgWKEG2NJL0fz0UhAeWywhUlrQrLB+ pOK6fFPxstW2Q== Date: Fri, 23 Oct 2026 09:35:50 -1000 Message-ID: From: Tejun Heo To: Kuba Piecuch Cc: Peter Zijlstra , David Vernet , Andrea Righi , Changwoo Min , sched-ext@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] sched/core: Preserve WF_RQ_SELECTED across queued wakeups In-Reply-To: <20261023144811.2230393-2-jpiecuch@google.com> References: <20261023144811.2230393-1-jpiecuch@google.com> <20261023144811.2230393-2-jpiecuch@google.com> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit On Fri, Oct 23, 2026 at 02:48:04PM +0000, Kuba Piecuch wrote: > ENQUEUE_RQ_SELECTED tells a sched_class that ->select_task_rq() was > called for a task wakeup. sched_ext exposes this flag to BPF schedulers > as SCX_ENQ_CPU_SELECTED. However, the flag is lost for queued wakeups, > which a BPF scheduler can opt into with SCX_OPS_ALLOW_QUEUED_WAKEUP. > This also results in undercounting SCX_EV_SELECT_CPU_FALLBACK events. > > Preserve WF_RQ_SELECTED for queued wakeups in the same way WF_MIGRATED > is. This way, ttwu_activate() receives WF_RQ_SELECTED for queued wakeups > and passes ENQUEUE_RQ_SELECTED to activate_task(). > > Fixes: 3539c6411a7c ("sched_ext: Implement SCX_OPS_ALLOW_QUEUED_WAKEUP") > Signed-off-by: Kuba Piecuch Acked-by: Tejun Heo Thanks. -- tejun