From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 9DAC438553F; Tue, 9 Jun 2026 09:18:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780996699; cv=none; b=RuCYfRs3S0gTdBGbX15boommdlA7HWJ7Rx3CZyJhTc+HbebodwxyzaMOYJBBBoiwP41Z9PPd8jLFCkyDfRD4GEx07dkBNUQ7nQOYdPkOgQDGnuC9gkid3xCVOmL+K8VfdLCHrW8Ln0xn5N39vo+RNuhtHNNDQGgcdo4m9G8C4YM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780996699; c=relaxed/simple; bh=IVEHRfJs06RFdJt5fadVmDHxis0F0C2uMWjdWg15O+4=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=kgYQ30wujMagwgxSRrFz2VjQJf1vYEV0zEpB9Kl35Zl9KrLIXXHjxvMt1rDerVQmF19bP/mT8JVNH0Op+kdIcUcCEAT4uFV9gqbCX4m3f2GMPWKZvfDYFFrz8yFbpFGwF0MArDzJRemor0mGeRGa+S/hA/hWVC+OTZGDI8JIHQs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=i0pCMfID; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="i0pCMfID" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C4EC41F00898; Tue, 9 Jun 2026 09:18:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780996698; bh=vfE2JW2NevESnpLgbLVUdD60WBjBFWnXxCfZNTt4csA=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=i0pCMfID9bPgEqXp+BuomAg5WrIvzYhOfvJqY8Ei3gYRGK/Z4sJZTnqnHcTvX2Mwi 0i3Jg6HQcgA/GmARey6i1OKtJw4jYxntAugYddhk7I6idIrD+LADXCIiZuEINYHl/s tsm0ts8vxezmbqWW/6yZRrUbmc8+goIoZjbXFgoP1OkjoFi4tp9w4jKbcch8JUt91l 2WikOVyJiq2Tz49q+qC1aTfw2Yn4L6vHvyGbPtMwZ8Ea15Gtz8hST67xZymsAbRMR/ GxBWiQMeA/EO6CJfjzYSacyiFrXDdxl9iwYPYmZ5eK9Htm5modRwIhzeZk7vccurBb xm8uC+Za6kDWQ== From: "Vlastimil Babka (SUSE)" Date: Tue, 09 Jun 2026 11:17:51 +0200 Subject: [PATCH RFC 06/15] mm/slab: replace struct partial_context with slab_alloc_context Precedence: bulk X-Mailing-List: cgroups@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: <20260609-slab_alloc_flags-v1-6-2bf4a4b9b526@kernel.org> References: <20260609-slab_alloc_flags-v1-0-2bf4a4b9b526@kernel.org> In-Reply-To: <20260609-slab_alloc_flags-v1-0-2bf4a4b9b526@kernel.org> To: Harry Yoo Cc: Hao Li , Christoph Lameter , David Rientjes , Roman Gushchin , Suren Baghdasaryan , Alexei Starovoitov , Andrew Morton , Johannes Weiner , Michal Hocko , Shakeel Butt , Alexander Potapenko , Marco Elver , Dmitry Vyukov , kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, "Vlastimil Babka (SUSE)" X-Mailer: b4 0.15.2 Refactor get_from_partial_node(), get_from_any_partial(), get_from_partial() and ___slab_alloc(). Remove struct partial_context, which used to be more substantial but shrank as part of the sheaves conversion. Instead pass gfp_flags and pointer to the new slab_alloc_context, which together is a superset of partial_context. This means alloc_flags are now available and we can use them to determine if spinning is allowed, further reducing false positive "not allowed" in the slow path due to gfp flags lacking __GFP_RECLAIM. Signed-off-by: Vlastimil Babka (SUSE) --- mm/slub.c | 52 ++++++++++++++++++++++++---------------------------- 1 file changed, 24 insertions(+), 28 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index b2a452dd70fa..0bde4f6d9126 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -220,12 +220,6 @@ struct slab_alloc_context { unsigned int alloc_flags; }; -/* Structure holding parameters for get_from_partial() call chain */ -struct partial_context { - gfp_t flags; - unsigned int orig_size; -}; - /* Structure holding parameters for get_partial_node_bulk() */ struct partial_bulk_context { gfp_t flags; @@ -3826,7 +3820,8 @@ static bool get_partial_node_bulk(struct kmem_cache *s, */ static void *get_from_partial_node(struct kmem_cache *s, struct kmem_cache_node *n, - struct partial_context *pc) + gfp_t gfp_flags, + struct slab_alloc_context *ac) { struct slab *slab, *slab2; unsigned long flags; @@ -3841,7 +3836,7 @@ static void *get_from_partial_node(struct kmem_cache *s, if (!n || !n->nr_partial) return NULL; - if (gfpflags_allow_spinning(pc->flags)) + if (alloc_flags_allow_spinning(ac->alloc_flags)) spin_lock_irqsave(&n->list_lock, flags); else if (!spin_trylock_irqsave(&n->list_lock, flags)) return NULL; @@ -3849,12 +3844,12 @@ static void *get_from_partial_node(struct kmem_cache *s, struct freelist_counters old, new; - if (!pfmemalloc_match(slab, pc->flags)) + if (!pfmemalloc_match(slab, gfp_flags)) continue; if (IS_ENABLED(CONFIG_SLUB_TINY) || kmem_cache_debug(s)) { object = alloc_single_from_partial(s, n, slab, - pc->orig_size); + ac->orig_size); if (object) break; continue; @@ -3888,15 +3883,16 @@ static void *get_from_partial_node(struct kmem_cache *s, /* * Get an object from somewhere. Search in increasing NUMA distances. */ -static void *get_from_any_partial(struct kmem_cache *s, struct partial_context *pc) +static void *get_from_any_partial(struct kmem_cache *s, gfp_t gfp_flags, + struct slab_alloc_context *ac) { #ifdef CONFIG_NUMA struct zonelist *zonelist; struct zoneref *z; struct zone *zone; - enum zone_type highest_zoneidx = gfp_zone(pc->flags); + enum zone_type highest_zoneidx = gfp_zone(gfp_flags); unsigned int cpuset_mems_cookie; - bool allow_spin = gfpflags_allow_spinning(pc->flags); + bool allow_spin = alloc_flags_allow_spinning(ac->alloc_flags); /* * The defrag ratio allows a configuration of the tradeoffs between @@ -3930,16 +3926,17 @@ static void *get_from_any_partial(struct kmem_cache *s, struct partial_context * if (allow_spin) cpuset_mems_cookie = read_mems_allowed_begin(); - zonelist = node_zonelist(mempolicy_slab_node(), pc->flags); + zonelist = node_zonelist(mempolicy_slab_node(), gfp_flags); for_each_zone_zonelist(zone, z, zonelist, highest_zoneidx) { struct kmem_cache_node *n; n = get_node(s, zone_to_nid(zone)); - if (n && cpuset_zone_allowed(zone, pc->flags) && + if (n && cpuset_zone_allowed(zone, gfp_flags) && n->nr_partial > s->min_partial) { - void *object = get_from_partial_node(s, n, pc); + void *object = get_from_partial_node(s, n, + gfp_flags, ac); if (object) { /* @@ -3961,8 +3958,8 @@ static void *get_from_any_partial(struct kmem_cache *s, struct partial_context * /* * Get an object from a partial slab */ -static void *get_from_partial(struct kmem_cache *s, int node, - struct partial_context *pc) +static void *get_from_partial(struct kmem_cache *s, int node, gfp_t flags, + struct slab_alloc_context *ac) { int searchnode = node; void *object; @@ -3970,11 +3967,11 @@ static void *get_from_partial(struct kmem_cache *s, int node, if (node == NUMA_NO_NODE) searchnode = numa_mem_id(); - object = get_from_partial_node(s, get_node(s, searchnode), pc); - if (object || (node != NUMA_NO_NODE && (pc->flags & __GFP_THISNODE))) + object = get_from_partial_node(s, get_node(s, searchnode), flags, ac); + if (object || (node != NUMA_NO_NODE && (flags & __GFP_THISNODE))) return object; - return get_from_any_partial(s, pc); + return get_from_any_partial(s, flags, ac); } static bool has_pcs_used(int cpu, struct kmem_cache *s) @@ -4454,16 +4451,16 @@ static void *___slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node, struct slab_alloc_context *ac) { bool allow_spin = alloc_flags_allow_spinning(ac->alloc_flags); + gfp_t trynode_flags; void *object; struct slab *slab; - struct partial_context pc; bool try_thisnode = true; stat(s, ALLOC_SLOWPATH); new_objects: - pc.flags = gfpflags; + trynode_flags = gfpflags; /* * When a preferred node is indicated but no __GFP_THISNODE * @@ -4479,17 +4476,16 @@ static void *___slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node, && try_thisnode)) { if (unlikely(!allow_spin)) /* Do not upgrade gfp to NOWAIT from more restrictive mode */ - pc.flags = gfpflags | __GFP_THISNODE; + trynode_flags = gfpflags | __GFP_THISNODE; else - pc.flags = GFP_NOWAIT | __GFP_THISNODE; + trynode_flags = GFP_NOWAIT | __GFP_THISNODE; } - pc.orig_size = ac->orig_size; - object = get_from_partial(s, node, &pc); + object = get_from_partial(s, node, trynode_flags, ac); if (object) goto success; - slab = new_slab(s, pc.flags, node); + slab = new_slab(s, trynode_flags, node); if (unlikely(!slab)) { if (node != NUMA_NO_NODE && !(gfpflags & __GFP_THISNODE) -- 2.54.0