From nobody Mon Feb 9 14:14:09 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 2520715B546 for ; Fri, 31 Jan 2025 07:10:05 +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=1738307407; cv=none; b=FS1jNmmV+OBYA/baxNUQ3+eKIGl6rgsV/9g+QJc3/VQ0DnkQB2ZBpWUQ58jrYgkFf+LG459O2TKvzkok9Rt9Ele5FboiqUbV650/4Phul0kJQPgFbGIGMVFFLgxzpnLVu6Nzy32LVM1IzW/b3DuKi147c/b3l9sFuhQzd0ZiT70= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738307407; c=relaxed/simple; bh=c1Il5sS3fT3lVg9aTCV1w+wu5xAvQXF+dUafJxi9yvY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=kTfWq50+3MhkFD3x48u6R9CqBKirAIYozE4BOpLz9uu8RV9uZXG6jjVRSMX6/+xaBgQrnhtLpjUDNomTDTNSPovoLxnrBKrct/VrHYaTolba6GnegRFEdoqlCAYwXLj1mzVIciJ4R4km3i4fK4SUhaUmDzfsx/99RQrwl2iARTo= 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=C6fTr8O+; 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="C6fTr8O+" 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=Ynq2LvCTfrKNO0aYPqmVtw2j6T8KCcEwVFZ3rO6djNY=; b=C6fTr8O+MvS331Ah+3j3neyvxf g1qVkjo+8kH1rWZD7FjLdU4rLNP0ilGZipfTBnzQZjyZoBrb64WSOy8PofUF4qKcjuMJANERLHLe4 t66RxSMVoVvTSTrvH6EQGB5S4M5IGUK0kDCeXgjhzSsI3SY1nI/7LZHTYGfT7b+GwdCqLfMDTNPas P1y1pCij2bfAYHVImEDF38GCdjV1f90BE3McSsD4CoynVVRd87mswEROoHlcA5sOqH/WlOeo6r2LM 4b+dy+PIaQLrF1S8I3f0zbfOd5PHIQz6fyL1B4+ajX8IpuNMDm6929Ca2QlZ4c0UpzC6GfV3wbpUz ZX/2PZ5A==; 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 1tdlA2-001KYq-BU; Fri, 31 Jan 2025 08:10:00 +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 03/11] sched_ext: Add an event, SCX_EV_DISPATCH_LOCAL_DSQ_OFFLINE Date: Fri, 31 Jan 2025 16:09:30 +0900 Message-ID: <20250131070938.95551-4-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_LOCAL_DSQ_OFFLINE, which represents how many times a BPF scheduler tries to dispatch to an offlined local DSQ. __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 4d3b32aca48d..041b0af3551a 100644 --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -1449,6 +1449,12 @@ struct scx_event_stats { * the core scheduler code silently picks a fallback CPU. */ u64 SCX_EV_SELECT_CPU_FALLBACK; + + /* + * When dispatching to a local DSQ, the CPU may have gone offline in + * the meantime. In this case, the task is bounced to the global DSQ. + */ + u64 SCX_EV_DISPATCH_LOCAL_DSQ_OFFLINE; }; =20 /* @@ -2644,6 +2650,7 @@ static void dispatch_to_local_dsq(struct rq *rq, stru= ct scx_dispatch_q *dst_dsq, if (unlikely(!task_can_run_on_remote_rq(p, dst_rq, true))) { dispatch_enqueue(find_global_dsq(p), p, enq_flags | SCX_ENQ_CLEAR_OPSS); + __scx_add_event(SCX_EV_DISPATCH_LOCAL_DSQ_OFFLINE, 1); return; } =20 @@ -4970,6 +4977,7 @@ static void scx_dump_state(struct scx_exit_info *ei, = size_t dump_len) =20 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); =20 if (seq_buf_has_overflowed(&s) && dump_len >=3D sizeof(trunc_marker)) memcpy(ei->dump + dump_len - sizeof(trunc_marker), @@ -7104,6 +7112,7 @@ __bpf_kfunc void scx_bpf_events(struct scx_event_stat= s *events, for_each_possible_cpu(cpu) { 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); } =20 /* --=20 2.48.1