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 BC1553F39E5; Tue, 9 Jun 2026 09:18:14 +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=1780996695; cv=none; b=rfO2zeBF9m6xTZa4r7Ja47/hJpfYzuxr6DABuezj9Flk9yFBMagE5PnruBGaL/mU+nNattXJfV5ZKJejqkRL2x9NM2alkrikZR7JkWStehIIu/uLTDZmSrkOn2eGOr9aHLf/MlllEZ91BPhdBonS1H/ukWwK+yIjHvcGiJw2hmw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780996695; c=relaxed/simple; bh=5FTOVjtxsumh5OVZ7SKtRSg3YXCwAY3OMkOa/2FT/bQ=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=fQSEQzphAi203lYAl9rcI1/XeWC/7lF6ieIZasFU+YUPl4vdMWbjts5XSwfqvZMpa1no3Tp3HpE2tnJ4E2hLWtQKx06WD23551lobfLbCT3yTgwAT051kU4ktyP5kjMFXJHUAHhOjP/zYWtwFa/sBB8eyCUbYr4GMUe7oFDYG8o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=fuQh7gWD; 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="fuQh7gWD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D762D1F00893; Tue, 9 Jun 2026 09:18:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780996694; bh=UaSnETjCVjKQXWJX1aoWsst86Gp93Bm51zl46Fnvd9Q=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=fuQh7gWDayJSvLXaB+wnx5dQuD5ZWO3KkG541FD7WN8TTBLqUfkzaQdPnG8Z972n8 FEEn1P++JxpaAG/u7Q51YwJ4k4indiGn8LAAOeiLW5b81km8G/bc48kOSuUaqUJucB WeJ4ZxSEzWNPDBKbVhwmmzqeawSPoZnDGZSbyI+aQ58Ol4HtjK9EIXCTNuxTkljNjv TBcqmly6vqldZyJX7J0CV24jhy3TUQvrOPyHgLSq/ZTu7faTh9UtfMAQK4yc2F/zO3 Tut+uyQ13I4Izx7CJe5Q3VuqQBSY3mq37X6VXKzwCbOxlevwCcEOPgvbIhc4GYZ529 crHcT/FegA1KQ== From: "Vlastimil Babka (SUSE)" Date: Tue, 09 Jun 2026 11:17:50 +0200 Subject: [PATCH RFC 05/15] mm/slab: add alloc_flags to 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-v1-5-2bf4a4b9b526@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 Add alloc_flags as a new field to the slab_alloc_context helper struct, so we can pass it to more functions in the slab implementation without adding another function parameter. Start checking them via alloc_flags_allow_spinning() in alloc_single_from_new_slab() (where we can drop the allow_spin parameter) and ___slab_alloc(). This further reduces false-positive spinning-not-allowed from allocations that are not kmalloc_nolock() but lack __GFP_RECLAIM flags. _kmalloc_nolock_noprof() initializes ac.alloc_flags using its flags that are SLAB_ALLOC_TRYLOCK. slab_alloc_node() and __kmem_cache_alloc_bulk() are not reachable from kmalloc_nolock() and all their callers expect spinning to be allowed, so they can use SLAB_ALLOC_DEFAULT. This is temporary as the scope of slab_alloc_context will further move to the callers, making the alloc_flags usage more obvious. Signed-off-by: Vlastimil Babka (SUSE) --- mm/slub.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index 278d8cbcc7ee..b2a452dd70fa 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -217,6 +217,7 @@ static DEFINE_STATIC_KEY_FALSE(strict_numa); struct slab_alloc_context { unsigned long caller_addr; unsigned long orig_size; + unsigned int alloc_flags; }; /* Structure holding parameters for get_from_partial() call chain */ @@ -3693,9 +3694,9 @@ static inline void init_slab_obj_iter(struct kmem_cache *s, struct slab *slab, * and put the slab to the partial (or full) list. */ static void *alloc_single_from_new_slab(struct kmem_cache *s, struct slab *slab, - struct slab_alloc_context *ac, - bool allow_spin) + struct slab_alloc_context *ac) { + bool allow_spin = alloc_flags_allow_spinning(ac->alloc_flags); struct kmem_cache_node *n; struct slab_obj_iter iter; bool needs_add_partial; @@ -4452,7 +4453,7 @@ static unsigned int alloc_from_new_slab(struct kmem_cache *s, struct slab *slab, static void *___slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node, struct slab_alloc_context *ac) { - bool allow_spin = gfpflags_allow_spinning(gfpflags); + bool allow_spin = alloc_flags_allow_spinning(ac->alloc_flags); void *object; struct slab *slab; struct partial_context pc; @@ -4503,7 +4504,7 @@ static void *___slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node, stat(s, ALLOC_SLAB); if (IS_ENABLED(CONFIG_SLUB_TINY) || kmem_cache_debug(s)) { - object = alloc_single_from_new_slab(s, slab, ac, allow_spin); + object = alloc_single_from_new_slab(s, slab, ac); if (likely(object)) goto success; @@ -4903,6 +4904,7 @@ unsigned int alloc_from_pcs_bulk(struct kmem_cache *s, gfp_t gfp, size_t size, static __fastpath_inline void *slab_alloc_node(struct kmem_cache *s, struct list_lru *lru, gfp_t gfpflags, int node, unsigned long addr, size_t orig_size) { + const unsigned int alloc_flags = SLAB_ALLOC_DEFAULT; void *object; s = slab_pre_alloc_hook(s, gfpflags); @@ -4913,12 +4915,13 @@ static __fastpath_inline void *slab_alloc_node(struct kmem_cache *s, struct list if (unlikely(object)) goto out; - object = alloc_from_pcs(s, gfpflags, SLAB_ALLOC_DEFAULT, node); + object = alloc_from_pcs(s, gfpflags, alloc_flags, node); if (unlikely(!object)) { struct slab_alloc_context ac = { .caller_addr = addr, .orig_size = orig_size, + .alloc_flags = alloc_flags, }; object = __slab_alloc_node(s, gfpflags, node, &ac); } @@ -5390,6 +5393,7 @@ void *_kmalloc_nolock_noprof(DECL_TOKEN_PARAMS(size, token), gfp_t gfp_flags, in struct slab_alloc_context ac = { .caller_addr = _RET_IP_, .orig_size = orig_size, + .alloc_flags = alloc_flags, }; /* @@ -7240,6 +7244,7 @@ static bool __kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, struct slab_alloc_context ac = { .caller_addr = _RET_IP_, .orig_size = s->object_size, + .alloc_flags = SLAB_ALLOC_DEFAULT, }; for (i = 0; i < size; i++) { -- 2.54.0