From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B02E633CEB3 for ; Wed, 27 Aug 2025 08:26:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.135.223.130 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756283205; cv=none; b=tJmhYhDSnsO61W63NVe54ZI2NsJk4m3OjsYRXN8DZbYAlHzItckyL0Kk3gG8Yz0ehegWbfDX+1ZCQF5umZrVobZG2n76GHJvPMtlE0JpMxqCkv01M6YVEN219rnXh000GbuQemaq7wjkRpHef/WMKgG//CBIfvDytQcqZG8cMrU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756283205; c=relaxed/simple; bh=v9obO0py9wopSX+MdWuhyrZ0RzarMmXuW475AFi3C+k=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=qDmlq7C6PAEQ+E6jCQG1uGF+NmjcN/yt3PpinzKbkJxhJsIM93MHrIi602WI8HA8Jcr6vo0CtFCeQKtnOytGIaXSwH/J99GsJxCHbDyaCYoKniDJzYQcEBkiUssO/jcoGeMguhI5SO/hhDp42DTBjBWDXW1O1KNANCPdbKAAOyw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz; spf=pass smtp.mailfrom=suse.cz; arc=none smtp.client-ip=195.135.223.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.cz Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [IPv6:2a07:de40:b281:104:10:150:64:97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 953222207C; Wed, 27 Aug 2025 08:26:35 +0000 (UTC) Authentication-Results: smtp-out1.suse.de; none Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id 7F96A13A31; Wed, 27 Aug 2025 08:26:35 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id 2KXgHjvBrmhNfgAAD6G6ig (envelope-from ); Wed, 27 Aug 2025 08:26:35 +0000 From: Vlastimil Babka Date: Wed, 27 Aug 2025 10:26:39 +0200 Subject: [PATCH v6 07/10] slab: allow NUMA restricted allocations to use percpu sheaves Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20250827-slub-percpu-caches-v6-7-f0f775a3f73f@suse.cz> References: <20250827-slub-percpu-caches-v6-0-f0f775a3f73f@suse.cz> In-Reply-To: <20250827-slub-percpu-caches-v6-0-f0f775a3f73f@suse.cz> To: Suren Baghdasaryan , "Liam R. Howlett" , Christoph Lameter , David Rientjes Cc: Roman Gushchin , Harry Yoo , Uladzislau Rezki , linux-mm@kvack.org, linux-kernel@vger.kernel.org, rcu@vger.kernel.org, maple-tree@lists.infradead.org, vbabka@suse.cz X-Mailer: b4 0.14.2 X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Rspamd-Action: no action X-Spam-Flag: NO X-Spam-Level: X-Rspamd-Server: rspamd2.dmz-prg2.suse.org X-Spamd-Result: default: False [-4.00 / 50.00]; REPLY(-4.00)[] X-Rspamd-Queue-Id: 953222207C X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Spam-Score: -4.00 Currently allocations asking for a specific node explicitly or via mempolicy in strict_numa node bypass percpu sheaves. Since sheaves contain mostly local objects, we can try allocating from them if the local node happens to be the requested node or allowed by the mempolicy. If we find the object from percpu sheaves is not from the expected node, we skip the sheaves - this should be rare. Reviewed-by: Harry Yoo Signed-off-by: Vlastimil Babka --- mm/slub.c | 53 ++++++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 46 insertions(+), 7 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index b37e684457e7d14781466c0086d1b64df2fd8e9d..aeaffcbca49b3e50ef345c3a6f24d007b53ef24e 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -4808,18 +4808,43 @@ __pcs_replace_empty_main(struct kmem_cache *s, struct slub_percpu_sheaves *pcs, } static __fastpath_inline -void *alloc_from_pcs(struct kmem_cache *s, gfp_t gfp) +void *alloc_from_pcs(struct kmem_cache *s, gfp_t gfp, int node) { struct slub_percpu_sheaves *pcs; + bool node_requested; void *object; #ifdef CONFIG_NUMA - if (static_branch_unlikely(&strict_numa)) { - if (current->mempolicy) - return NULL; + if (static_branch_unlikely(&strict_numa) && + node == NUMA_NO_NODE) { + + struct mempolicy *mpol = current->mempolicy; + + if (mpol) { + /* + * Special BIND rule support. If the local node + * is in permitted set then do not redirect + * to a particular node. + * Otherwise we apply the memory policy to get + * the node we need to allocate on. + */ + if (mpol->mode != MPOL_BIND || + !node_isset(numa_mem_id(), mpol->nodes)) + + node = mempolicy_slab_node(); + } } #endif + node_requested = IS_ENABLED(CONFIG_NUMA) && node != NUMA_NO_NODE; + + /* + * We assume the percpu sheaves contain only local objects although it's + * not completely guaranteed, so we verify later. + */ + if (unlikely(node_requested && node != numa_mem_id())) + return NULL; + if (!local_trylock(&s->cpu_sheaves->lock)) return NULL; @@ -4831,7 +4856,21 @@ void *alloc_from_pcs(struct kmem_cache *s, gfp_t gfp) return NULL; } - object = pcs->main->objects[--pcs->main->size]; + object = pcs->main->objects[pcs->main->size - 1]; + + if (unlikely(node_requested)) { + /* + * Verify that the object was from the node we want. This could + * be false because of cpu migration during an unlocked part of + * the current allocation or previous freeing process. + */ + if (folio_nid(virt_to_folio(object)) != node) { + local_unlock(&s->cpu_sheaves->lock); + return NULL; + } + } + + pcs->main->size--; local_unlock(&s->cpu_sheaves->lock); @@ -4931,8 +4970,8 @@ static __fastpath_inline void *slab_alloc_node(struct kmem_cache *s, struct list if (unlikely(object)) goto out; - if (s->cpu_sheaves && node == NUMA_NO_NODE) - object = alloc_from_pcs(s, gfpflags); + if (s->cpu_sheaves) + object = alloc_from_pcs(s, gfpflags, node); if (!object) object = __slab_alloc_node(s, gfpflags, node, addr, orig_size); -- 2.51.0