From nobody Mon Feb 9 17:35:08 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 6EC101714C6 for ; Fri, 31 Jan 2025 07:10:11 +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=1738307413; cv=none; b=mi2FHaK4TRal0W1Piqqgzb7FHk4Pdiohdtj75NWzHQ5Mb0hsY17XqBYIu2N7+0PSis4d5LxvA07YA2xOjUdM2qmsCIqE9Lk5GIo6yCmF+mM2BgdnafrcSzGX/JqZUXo4e4uik5Cn2EHE8/YmrMfphR3LSaeiRRJB0qlHys9Nj60= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738307413; c=relaxed/simple; bh=8vHu4xE+SSmDHI0c8AnDSXYni7h7urbVNTurAdRsVuU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=PebSrpsx5b337r3V74TZuiXhV8wmLzaELPhK8um7KJAojpclS/pL00wH+BRK5+Vmui0TIA0CHn8o30R2NWFV54MdRm13vhD73pK6qDa033reZLtrRF8nQoTw+dyvTRLw9D3Av+E3wOgtco5LJimrTU7bFt30H7jANzbpwiZfxEA= 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=ZhHMT+Wy; 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="ZhHMT+Wy" 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=AOi9u7Zk84KsH8av/AW4gcZtLuwHZ/58/8SnsZwDWjg=; b=ZhHMT+Wym/x/QXRWjybr2beVeU +Ssqssn9zrkNZ5Rbli70GQtjXtl2MrfNzXoAylljMWkSiQpYapX9nOSidHbqdEx8tIiDMBEbqbAuR Vx1capXZYtw+6JK/LpWgu7RWgikI5j9TqGisLsCXte9dQ2jk7VCRuBQjlR2WelSjoyeWiGMWCFFap JqBIxkuofGQkKMfelAiqMeglx6b8ccg2Nxh/3xq0TWWRvYPUqTnxlKQgMTNXKhgPodRwejUsICgnJ eh1Ik5oZWcDfwXjfsHEVJCO2ni58GkLabbx+1/raFgrvN5ZO96BF/ibSsHcjy/7Zjfbwicxgi0P/k 8CkPLnHw==; 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 1tdlA6-001KZB-Lz; Fri, 31 Jan 2025 08:10:05 +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 v3 04/11] sched_ext: Add an event, SCX_EV_DISPATCH_KEEP_LAST Date: Fri, 31 Jan 2025 16:09:31 +0900 Message-ID: <20250131070938.95551-5-changwoo@igalia.com> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250131070938.95551-1-changwoo@igalia.com> References: <20250131070938.95551-1-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, SCX_EV_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 041b0af3551a..7147f730850b 100644 --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -1455,6 +1455,12 @@ struct scx_event_stats { * the meantime. In this case, the task is bounced to the global DSQ. */ u64 SCX_EV_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 SCX_EV_DISPATCH_KEEP_LAST; }; =20 /* @@ -2908,6 +2914,7 @@ 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(SCX_EV_DISPATCH_KEEP_LAST, 1); goto has_tasks; } rq->scx.flags &=3D ~SCX_RQ_IN_BALANCE; @@ -4978,6 +4985,7 @@ static void scx_dump_state(struct scx_exit_info *ei, = size_t dump_len) scx_bpf_events(&events, sizeof(events)); scx_dump_event(s, &events, SCX_EV_SELECT_CPU_FALLBACK); scx_dump_event(s, &events, SCX_EV_DISPATCH_LOCAL_DSQ_OFFLINE); + scx_dump_event(s, &events, SCX_EV_DISPATCH_KEEP_LAST); =20 if (seq_buf_has_overflowed(&s) && dump_len >=3D sizeof(trunc_marker)) memcpy(ei->dump + dump_len - sizeof(trunc_marker), @@ -7113,6 +7121,7 @@ __bpf_kfunc void scx_bpf_events(struct scx_event_stat= s *events, e_cpu =3D per_cpu_ptr(&event_stats_cpu, cpu); scx_agg_event(&e_sys, e_cpu, SCX_EV_SELECT_CPU_FALLBACK); scx_agg_event(&e_sys, e_cpu, SCX_EV_DISPATCH_LOCAL_DSQ_OFFLINE); + scx_agg_event(&e_sys, e_cpu, SCX_EV_DISPATCH_KEEP_LAST); } =20 /* --=20 2.48.1