From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from SJ2PR03CU001.outbound.protection.outlook.com (mail-westusazon11012022.outbound.protection.outlook.com [52.101.43.22]) (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 6BD6237B41F for ; Fri, 25 Sep 2026 14:46:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=52.101.43.22 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790347591; cv=fail; b=lPDibKq/jyqaY95pyr/qRAnqetTz26v52Vaeuh4ZSyWidr1GZfJu500NRj1HDksr7VLyu01lzBrSTYpgBZw+cAC33uOfUTA8Nsm38ng1AKc6gAJ+2ecxxi1gbMpRjNehu7RLpspTW0bLXhvfImWilTxq6ChkRfMJ69Ws6BN8Hw8= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790347591; c=relaxed/simple; bh=aZ6ntxiMGcfUKYHwhvi9yMv3p70Zzx/SQZHeTydk6cw=; h=From:To:Cc:Subject:Date:Message-ID:Content-Type:MIME-Version; b=KsRRm2ZTuAfY6p9KocQqntQjDZIZCpQnHSvQ0rjjEGf7MWHJmR69Hl8DXKhUV1nVC/EIrKZHmVImvDmE5Akmwlm6nspqVsFRHh9/bIjzTotgYlMuu5iaTk8my3/m1G+B9Npvl9t0reQAFgiJwGdYTBhF9qtV/V8UxqQMeHGduJQ= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com; spf=fail smtp.mailfrom=nvidia.com; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b=b1V6QtHp; arc=fail smtp.client-ip=52.101.43.22 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=nvidia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b="b1V6QtHp" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=b67c+QwzkiHHiIXdab+5Hm7G1b6clcc5tRTeRt3N1wVIHJMLfEX4e4Tk2hyZ634yF7Ao7YJPp4Znf0h2DisHFJwHOFTZEHFhB50DZXZzfh1YPPxJzvWqyI5qJAibHTv/50/Rg80tj/fBSBe3Ea6Nvxa5oFWQnWe/FAdhYZOiMv6Fqvyq2tLqODWI5RDJ+TpIgq45Nist25wPLOLpVHzhgEnDogkIKaXR8FoqRK58i0jg6bfJx4eN0jndUbX64PCBFKbOVwyQxgfHZqKqqrotDQVSgCjjifV8K3eEswp+pLYfmfDvZC2bW2wHvXfpX9dJ/vPubpi8DccvhSYT8x22NA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=dY9fjEpQviPdpc6gSYUkf0elKI6OD+x1HzLWPeDSKRg=; b=wPXlKulrujFD5jzwYqxwN6vlwp3jE35S523OlR087LAkTeK6fb+1sti3v7nl6yjNFoNdWtyhjyFPjS9zFdB9JkyNOcEziEApscH6McogcGjfEXGpPbDg+rjXKtZ0A3H1gRG430eXkkYzB7Unu01wSr19pPRRw7C+YuzG4zl4AOTR0VitQ2mePuAn89iAJLzY5gL5vWeq3587KaBjab+zGyFszI8lK6ala4ZIl2XTRCHeuZPdn8z2GIp6uYeB/iZLsdF6FlpfIJOVXvH5FZz2WWjU04Vuo6lkGJhMjnEIUIz5yTONpFla/ZmLHujTD2s16rA6hK9+TR/1PfQxmWj1eg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nvidia.com; dmarc=pass action=none header.from=nvidia.com; dkim=pass header.d=nvidia.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=dY9fjEpQviPdpc6gSYUkf0elKI6OD+x1HzLWPeDSKRg=; b=b1V6QtHpSnwAbRAik8OLiBM+azPRHHMU1gxTHBC1k6TNXReSMyghTCQw3Eu7PpkMqZqI5wipFdc2PDW2sxZ8bKDb+scUpC9omETtUNnm/8Ji6r+Dk/Awmh1FIOhKZAn3HNU+GIex0lyQHIteW5thV0KnYPGBBZhqC+l5qYk8Kk/IHbI9nQL4Hlp1V19qrw64RJH9dSuL8fvrA15hsyytW6OHYFEOqn2lqLI0PR7kZkTMaNWi9iBO6BCHndjqIHJSGOzrtI38zoxSs/tobX7LQD7s7A2kFJ3c5dbz6/4i+gZ6Zur4SMRMG4FLFnyZ615p2Vxej1unf/KGRx2GF6BXbg== Authentication-Results: mx.microsoft.com 1; dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from DM6PR12MB4827.namprd12.prod.outlook.com (2603:10b6:5:1d6::14) by PH8PR12MB6721.namprd12.prod.outlook.com (2603:10b6:510:1cc::18) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.451.18; Fri, 25 Sep 2026 14:46:18 +0000 Received: from DM6PR12MB4827.namprd12.prod.outlook.com ([fe80::6261:3040:864b:159c]) by DM6PR12MB4827.namprd12.prod.outlook.com ([fe80::6261:3040:864b:159c%3]) with mapi id 15.21.0451.014; Fri, 25 Sep 2026 14:46:17 +0000 From: Andrea Righi To: Tejun Heo , David Vernet , Changwoo Min Cc: Emil Tsalapatis , sched-ext@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH sched_ext/for-7.4] sched_ext: Add a CID NUMA node lookup kfunc Date: Fri, 25 Sep 2026 16:46:04 +0200 Message-ID: <20260925144604.2451177-1-arighi@nvidia.com> X-Mailer: git-send-email 2.55.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-ClientProxiedBy: ZR2P278CA0051.CHEP278.PROD.OUTLOOK.COM (2603:10a6:910:53::6) To DM6PR12MB4827.namprd12.prod.outlook.com (2603:10b6:5:1d6::14) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DM6PR12MB4827:EE_|PH8PR12MB6721:EE_ X-MS-Office365-Filtering-Correlation-Id: 411be744-b415-459b-ec0d-08df1b13c16b X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|23010399003|376014|1800799024|366016|10067099003|5023799004|6133799003|18002099003|56012099006|11063799006; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DM6PR12MB4827.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(23010399003)(376014)(1800799024)(366016)(10067099003)(5023799004)(6133799003)(18002099003)(56012099006)(11063799006);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?AHT+SWxkTP55552k+GaSaOugYSrUMYGn3csGbJj7WMRovYBanJ11gDha0uZM?= =?us-ascii?Q?r7WIVpNrMMnOG2wHwpxwa2EHL1+BSj4REqFfeW4DzR3vxuLX03GResedvubV?= =?us-ascii?Q?IhGrgO+R2/05dYPhVf2MVJDYhqnnU6sxWCrFALlcHndmaUK9NbgfR8v9T5Tw?= =?us-ascii?Q?A+/QhJiL8Pe/2mgL0/ammlPtNfE8YnevoM4+PZGlT2wZknt1bwGnU7VrqQ0E?= =?us-ascii?Q?0n+nJRiGzedSiwxMbzsB6Sm6CmPVBoIl8Lzhrrb5CzlEyjI/UNxykDnVrmUj?= =?us-ascii?Q?AFsB1pNAFi4s+tEWw+oHCHrSP5hQW2oIHKePSI8cxonOh3mpqkWL+1eXce14?= =?us-ascii?Q?cWDQn6fLAOAgv+sFOgxusnWLUNzu518bwwVvnJj4CjMVkzhS7FWI4y+HKMnR?= =?us-ascii?Q?9rMWI+ltuS4+uZV6VbGFfHOZEXNMwbkwRLCfLKbfia+uz1Pz9f2Gv5XChYvk?= =?us-ascii?Q?X3y3301cZOQaFPxyyVIZQsOyuzihthHxIrM/pyQt7oqiUJZKL7VLaZ74KKvs?= =?us-ascii?Q?1YL7Lwq1VnGWu9+3U5FfES2fGpeL/ItZRKAsss2NiEldExDPujzDNA/WVZ0j?= =?us-ascii?Q?H5X7Lye/QSmvIIF2JMSkEx2tZWrpUnK4CueAc2tP5wZC6ENCF4j2RllChcy0?= =?us-ascii?Q?23mkjvejHYs395qq3E9Huo1IcijiML3YvcJLbEJcirRSWLqUaXnp8PpwYgBi?= =?us-ascii?Q?bB91qBmyJAJ486Xlywaz/P36+JPMueqJBzHkSStOcX0lw85tU5KS9oWyaj9T?= =?us-ascii?Q?wvo3MPCjSSMknGOZlIve1klp1kVyCx8Ua6Atj+TXpJMAXjc5BL1H8NLT2l6I?= =?us-ascii?Q?s1khKxwbjYd3+NEboXRHGaa7qa/WnbAIZzB5bAbx6ys7EDGz0DpKOUha8Vtw?= =?us-ascii?Q?Fr9EfM7/ZuopQsdiThcz/pBx26mQ6xYo/rr81k0oOdxon2/VzaGYTW0QLZyc?= =?us-ascii?Q?sk5/XtilHIhuRoLGlOCzmOBiFED17qN3ku4vQt65PGryoA+AQ06RXIWwrEAw?= =?us-ascii?Q?ZdXpr2wdSDQpKwYh3y8wUhbH2ohSxqO8iP2WVK7GBNmQsGGNoRBmHCYTmZBA?= =?us-ascii?Q?iTmHGpl5qqGXYp6enuSEAputuhuyTziTb9RpeIRDzOnJTKvExoCQuaC7cdTK?= =?us-ascii?Q?QIrUMnot1mBlZDHmUhK7PlA9N9Qho72SveXe3GorRodHqU41qvzxW9OLSf0/?= =?us-ascii?Q?EvhJ+XMmhRwq1hReAAV8LzM6h+/RRsesn/GZGyM7l/HDB3Wf6Lgp+PCS1RbB?= =?us-ascii?Q?yWy6A/p3S0dGlVCaFJuE+/7ENmaOYdKxPhngZTVY2La87cc1cnshdoQfsA5z?= =?us-ascii?Q?ii26rLj4rgh3pFkuYbUqsF3DEVVRoVhe2nNAdl7T8AHR1QtCG3PR7geoq1OZ?= =?us-ascii?Q?5tnRlcZ3aVNxkhsvZSs+N1CSfENKazRgEDLRkC6QFObAeaQe1zQPW10zjoXr?= =?us-ascii?Q?Ocani8H4KnzXXI/AhMR5mYJcFJqarYjWJL9uvjEoimH7//rqJXj6YhPKb4W1?= =?us-ascii?Q?N+tpRqVIRbomL1BOzddFXuLCxleIRg4g8zmA6Ir1K6x358yEqe/1ZTYI8D1c?= =?us-ascii?Q?sobOKvK00KvL3HYzm2Q6oXHeH4uL+2H8qG7NgrnWqQQd7yNnrJeL8UVYn5u+?= =?us-ascii?Q?El6/kE6tcL6jNqQOTFxL84jOYWFlKzS4WSeMYR5R2OfKWaXtDDCZ5CS/TOA7?= =?us-ascii?Q?Qcj4YzXVBAd1xp9ZHcqjVckcNEDfErkAERB17l6gbdJvGa1tRiZ8leP9svZU?= =?us-ascii?Q?If+bn/suHg=3D=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 411be744-b415-459b-ec0d-08df1b13c16b X-MS-Exchange-CrossTenant-AuthSource: DM6PR12MB4827.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 25 Sep 2026 14:46:17.4681 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: R/fnk4swo8ZeivQVS5+STij+O8dLew7mBAiDqhxnpMbNGAbm0CeyQHel8IQGGnOjzhknW4qAvdpdwnHFj4AJqQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH8PR12MB6721 CID-form schedulers may need the physical NUMA node for a CID, for example to allocate arena memory on that node. The CID topology's node index is not a physical NUMA node ID, and scx_bpf_cpu_node() is restricted to CPU-form schedulers. Add scx_bpf_cid_node() to return the physical NUMA node for a CID and provide a compatibility helper that returns NUMA_NO_NODE on kernels without this kfunc. Signed-off-by: Andrea Righi --- kernel/sched/ext/cid.c | 24 ++++++++++++++++++++++++ tools/sched_ext/include/scx/common.bpf.h | 1 + tools/sched_ext/include/scx/compat.bpf.h | 5 +++++ 3 files changed, 30 insertions(+) diff --git a/kernel/sched/ext/cid.c b/kernel/sched/ext/cid.c index 39f88deb94bc4..932f640ccc2d8 100644 --- a/kernel/sched/ext/cid.c +++ b/kernel/sched/ext/cid.c @@ -640,6 +640,29 @@ __bpf_kfunc s32 scx_bpf_cid_to_cpu(s32 cid, const struct bpf_prog_aux *aux) return scx_cid_to_cpu(sch, cid); } +/** + * scx_bpf_cid_node - Return the NUMA node the given @cid belongs to + * @cid: cid to look up + * @aux: implicit BPF argument to access bpf_prog_aux hidden from BPF progs + * + * Return NUMA_NO_NODE if @cid is invalid or there is no scheduler. Unlike + * scx_bpf_cpu_node(), this kfunc is available only with CID support, so BPF + * schedulers can use its presence to detect NUMA-aware CID lookups. + */ +__bpf_kfunc s32 scx_bpf_cid_node(s32 cid, const struct bpf_prog_aux *aux) +{ + struct scx_sched *sch; + s32 cpu; + + guard(rcu)(); + + sch = scx_prog_sched(aux); + if (unlikely(!sch)) + return NUMA_NO_NODE; + cpu = scx_cid_to_cpu(sch, cid); + return cpu < 0 ? NUMA_NO_NODE : cpu_to_node(cpu); +} + /** * scx_bpf_cpu_to_cid - Return the cid for @cpu * @cpu: cpu to look up @@ -952,6 +975,7 @@ static const struct btf_kfunc_id_set scx_kfunc_set_init_cids = { BTF_KFUNCS_START(scx_kfunc_ids_cid) BTF_ID_FLAGS(func, scx_bpf_cid_to_cpu, KF_IMPLICIT_ARGS) +BTF_ID_FLAGS(func, scx_bpf_cid_node, KF_IMPLICIT_ARGS) BTF_ID_FLAGS(func, scx_bpf_cpu_to_cid, KF_IMPLICIT_ARGS) BTF_ID_FLAGS(func, scx_bpf_cid_topo, KF_IMPLICIT_ARGS) BTF_KFUNCS_END(scx_kfunc_ids_cid) diff --git a/tools/sched_ext/include/scx/common.bpf.h b/tools/sched_ext/include/scx/common.bpf.h index 9660b43d612ce..41342f1bdd311 100644 --- a/tools/sched_ext/include/scx/common.bpf.h +++ b/tools/sched_ext/include/scx/common.bpf.h @@ -106,6 +106,7 @@ u64 scx_bpf_now(void) __ksym __weak; void scx_bpf_events(struct scx_event_stats *events, size_t events__sz) __ksym __weak; s32 scx_bpf_cpu_to_cid(s32 cpu) __ksym __weak; s32 scx_bpf_cid_to_cpu(s32 cid) __ksym __weak; +s32 scx_bpf_cid_node(s32 cid) __ksym __weak; void scx_bpf_cid_topo(s32 cid, struct scx_cid_topo *out) __ksym __weak; void scx_bpf_kick_cid(s32 cid, u64 flags) __ksym __weak; s32 scx_bpf_task_cid(const struct task_struct *p) __ksym __weak; diff --git a/tools/sched_ext/include/scx/compat.bpf.h b/tools/sched_ext/include/scx/compat.bpf.h index 7d870331b2a6b..c5c90d1d81e04 100644 --- a/tools/sched_ext/include/scx/compat.bpf.h +++ b/tools/sched_ext/include/scx/compat.bpf.h @@ -243,6 +243,11 @@ static inline bool __COMPAT_is_enq_cpu_selected(u64 enq_flags) scx_bpf_pick_any_cpu_node(cpus_allowed, node, flags) : \ scx_bpf_pick_any_cpu(cpus_allowed, flags)) +/* v7.4: Add scx_bpf_cid_node(). */ +#define __COMPAT_scx_bpf_cid_node(cid) \ + (bpf_ksym_exists(scx_bpf_cid_node) ? \ + scx_bpf_cid_node(cid) : NUMA_NO_NODE) + /* * v6.18: Add a helper to retrieve the current task running on a CPU. * -- 2.55.0