From nobody Tue Feb 10 04:33:07 2026 Received: from fanzine2.igalia.com (fanzine.igalia.com [178.60.130.6]) (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 EA0AA16F0FE for ; Sun, 26 Jan 2025 10:16:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=178.60.130.6 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737886607; cv=none; b=f3lGQ1h5Xb0eJ4Gkju4q45rw5pbyHOv0dzIbjL8hOX2pbmVDWu2u9xI7cv4fMn7eOGY5xhBquHG/5FvTL6w2rZd5OLslL6KPG/rf6PHrtEFzOP6mXZMU1pz4EH+lFR09XQOlFBF0ulCTlJ+sp8QgeASBexr0lTq2LkfoVR7UrNA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737886607; c=relaxed/simple; bh=jvn6M1H82lAPFjaam6d8ioO5412AzdXJQMOjF4pehxE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=NM0ef4lsXhc/QYcz4QoH6ivKbGWr+mSYIq8eS/uEin4UJF0D6E02cfEyZkGm48ZoreQAwy5BpU6Yd/oJ4TpMq1wWXwJ6vCLOBQNQ8IKAxWpABku8aMrax1OTlYechEoOYOFIaK3vNQVjUX1csJvX9j9I/Q/aCo0l2ToRpzmfBsA= 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=LcRCtiMh; arc=none smtp.client-ip=178.60.130.6 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="LcRCtiMh" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=R48sgLH8zDXen4TRES0X+oz+R/agplkssVKv0K4R94g=; b=LcRCtiMh7kPGex3+1npEHk/UZt v0pm3hO1pToCgQCEiKxa3YkEqQd8qrQfxphDBfttOl2XEzWHGr2I7NFrY5UvoidwYNvK3XRMunko5 +WFg0ypynqFkA9EzcSUwEuhuwVoMKT7Oja63xMMkFscr7GbrpvwL53tsBl3wVVmSQk2QCTHeAk6Yr X+lVD4CVU4kAi4peAZSFdJ+fgrkhUBOuPebCREziVQEUoplF529i7FJDPVW+67xW0QvoFPICQWur8 HvNgACqRkTCSOkyB2ukliAq+BPT6WutgXG8YFg104rQni+kAn7fLSb4CJxqvvJIrDqA+YzqWM/rCS JQ+xnlDQ==; Received: from [58.29.143.236] (helo=localhost) by fanzine2.igalia.com with utf8esmtpsa (Cipher TLS1.3:ECDHE_SECP256R1__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim) id 1tbzh1-002ljP-Jl; Sun, 26 Jan 2025 11:16:39 +0100 From: Changwoo Min To: tj@kernel.org, void@manifault.com, arighi@nvidia.com Cc: kernel-dev@igalia.com, linux-kernel@vger.kernel.org, Changwoo Min Subject: [PATCH v2 05/11] sched_ext: Add an event, DISPATCH_KEEP_LAST Date: Sun, 26 Jan 2025 19:16:08 +0900 Message-ID: <20250126101614.232388-6-changwoo@igalia.com> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250126101614.232388-1-changwoo@igalia.com> References: <20250126101614.232388-1-changwoo@igalia.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Add a core event, DISPATCH_KEEP_LAST, which represents how many times a task is continued to run without ops.enqueue() when SCX_OPS_ENQ_LAST is not set. __scx_add_event() is used since the caller holds an rq lock, so the preemption has already been disabled. Signed-off-by: Changwoo Min --- kernel/sched/ext.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c index 38cf7ea6c385..d3a1ef58202c 100644 --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -1473,6 +1473,12 @@ struct scx_event_stats { * the meantime. In this case, the task is bounced to the global DSQ. */ u64 DISPATCH_LOCAL_DSQ_OFFLINE; + + /* + * If SCX_OPS_ENQ_LAST is not set, the number of times that a task + * continued to run because there were no other tasks on the CPU. + */ + u64 DISPATCH_KEEP_LAST; }; =20 /* @@ -2915,6 +2921,7 @@ static int balance_one(struct rq *rq, struct task_str= uct *prev) if (prev_on_rq && (!static_branch_unlikely(&scx_ops_enq_last) || scx_rq_bypassing(rq))) { rq->scx.flags |=3D SCX_RQ_BAL_KEEP; + __scx_add_event(DISPATCH_KEEP_LAST, 1); goto has_tasks; } rq->scx.flags &=3D ~SCX_RQ_IN_BALANCE; @@ -5500,6 +5507,7 @@ static void scx_dump_state(struct scx_exit_info *ei, = size_t dump_len) scx_bpf_event_stats(&events, sizeof(events)); scx_dump_event(s, &events, SELECT_CPU_FALLBACK); scx_dump_event(s, &events, DISPATCH_LOCAL_DSQ_OFFLINE); + scx_dump_event(s, &events, DISPATCH_KEEP_LAST); =20 if (seq_buf_has_overflowed(&s) && dump_len >=3D sizeof(trunc_marker)) memcpy(ei->dump + dump_len - sizeof(trunc_marker), @@ -7830,6 +7838,7 @@ __bpf_kfunc void scx_bpf_event_stats(struct scx_event= _stats *events, e_cpu =3D per_cpu_ptr(&event_stats_cpu, cpu); scx_agg_event(&e_sys, e_cpu, SELECT_CPU_FALLBACK); scx_agg_event(&e_sys, e_cpu, DISPATCH_LOCAL_DSQ_OFFLINE); + scx_agg_event(&e_sys, e_cpu, DISPATCH_KEEP_LAST); } =20 /* --=20 2.48.1