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 D7B1C43CEED; Wed, 10 Jun 2026 15:41:56 +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=1781106117; cv=none; b=m0YC3vFL+vAEW3slJcftcO2YKoidDewdcf+FchlyJFeG8iy4SU0dJrBrBkYquqbdj/Ampn/kRkDyQQdxxQdIuSGyOcfk3toDoJI3s1l6ChdlsQxPzBA0DjkiQ3d99cmubBrOgN7Nu1aw/Duzeisgjdj72Kk/8Xe70RepO0vVgTo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781106117; c=relaxed/simple; bh=Svx1vtCi0eqoMNa9zi5XKXmuF9MKi0bJitn7U2YLQoA=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=thOB+NbFJFNqWnjM+ryhoHlifc/EcvhW0X50q45ti7pPrDBXJdN/NafTgiKG9PiHzcllnYWglKDAuF69vVA24MCaJDDSNDTn96JaqxMFtXWyL4MU9ZBVfUaVkC4ATq21+DSSy6Ru0UvpkdbuRP7Rw/XUYPm8poswOkFiQSjTOho= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=euWmhiL/; 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="euWmhiL/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9314D1F00898; Wed, 10 Jun 2026 15:41:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1781106116; bh=rAo2TJ3mFhvqnm70uvjWd4gD385rP/fi/7KGDakhPn4=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=euWmhiL/lEvXt05tpNb7MhFHmWkvYpZ58BpFYeH7WWhqmkxsGJptakcG9Tjvx5MXP AAm3LKcSUpQQJ3uRGAZAz7MhaYb+6B/7dt2i0ANpYjZB9ijvCnbHhcKlGgON7+MWVI 4NwcuqOiBWKZ8zhi3GDUjoKO5pbpCFctoQ8etmybEEa7Fy397FfQhD2XIfcO8M4wzM /XD5DmzJNSoc4ol0L8l/TniwRG9kjwNbZ02/XbK+T4rKfUP3OujCgiJ3qS5ar+BPFv nt6pJkH8khzEKPIQJpqsD+JkJ15LYSaiZaCapgcPBo06od3ClLgqHJPW0UJwg58cFh zHE4WI5ZLiZgQ== From: "Vlastimil Babka (SUSE)" Date: Wed, 10 Jun 2026 17:40:15 +0200 Subject: [PATCH v2 13/16] mm/slab: allow __GFP_NOMEMALLOC and __GFP_NOWARN for kmalloc_nolock() 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: <20260610-slab_alloc_flags-v2-13-7190909db118@kernel.org> References: <20260610-slab_alloc_flags-v2-0-7190909db118@kernel.org> In-Reply-To: <20260610-slab_alloc_flags-v2-0-7190909db118@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 The two flags are added internally so there's no point for warning if they are passed by the caller as well, so allow them. This will allow simplifying obj_ext allocation under kmalloc_nolock(). Also it's not necessary to have the extra alloc_gfp variable for adding the two flags. The original gfp_flags parameter is not used anywhere except for the warning. So remove alloc_gfp and directly modify and use gfp_flags everywhere. Signed-off-by: Vlastimil Babka (SUSE) --- include/linux/slab.h | 3 ++- mm/slub.c | 19 ++++++++++--------- 2 files changed, 12 insertions(+), 10 deletions(-) diff --git a/include/linux/slab.h b/include/linux/slab.h index ce1c867dc0ba..b955f3cbb732 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -1040,7 +1040,8 @@ void *_kmalloc_nolock_noprof(DECL_TOKEN_PARAMS(size, token), gfp_t gfp_flags, in * kmalloc_nolock - Allocate an object of given size from any context. * @size: size to allocate * @gfp_flags: GFP flags. Only __GFP_ACCOUNT, __GFP_ZERO, __GFP_NO_OBJ_EXT - * allowed. + * allowed. Also __GFP_NOWARN and __GFP_NOMEMALLOC are allowed but added + * internally thus not necessary. * @node: node number of the target node. * * Return: pointer to the new object or NULL in case of error. diff --git a/mm/slub.c b/mm/slub.c index 6845e15c148a..847cad5203b2 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -5388,7 +5388,6 @@ EXPORT_SYMBOL(__kmalloc_noprof); void *_kmalloc_nolock_noprof(DECL_TOKEN_PARAMS(size, token), gfp_t gfp_flags, int node) { - gfp_t alloc_gfp = __GFP_NOWARN | __GFP_NOMEMALLOC | gfp_flags; size_t orig_size = size; unsigned int alloc_flags = SLAB_ALLOC_TRYLOCK; struct kmem_cache *s; @@ -5396,7 +5395,9 @@ void *_kmalloc_nolock_noprof(DECL_TOKEN_PARAMS(size, token), gfp_t gfp_flags, in void *ret; VM_WARN_ON_ONCE(gfp_flags & ~(__GFP_ACCOUNT | __GFP_ZERO | - __GFP_NO_OBJ_EXT)); + __GFP_NO_OBJ_EXT | __GFP_NOWARN | __GFP_NOMEMALLOC)); + + gfp_flags |= __GFP_NOWARN | __GFP_NOMEMALLOC; if (unlikely(!size)) return ZERO_SIZE_PTR; @@ -5415,7 +5416,7 @@ void *_kmalloc_nolock_noprof(DECL_TOKEN_PARAMS(size, token), gfp_t gfp_flags, in retry: if (unlikely(size > KMALLOC_MAX_CACHE_SIZE)) return NULL; - s = kmalloc_slab(size, NULL, alloc_gfp, PASS_TOKEN_PARAM(token)); + s = kmalloc_slab(size, NULL, gfp_flags, PASS_TOKEN_PARAM(token)); if (!(s->flags & __CMPXCHG_DOUBLE) && !kmem_cache_debug(s)) /* @@ -5429,7 +5430,7 @@ void *_kmalloc_nolock_noprof(DECL_TOKEN_PARAMS(size, token), gfp_t gfp_flags, in */ return NULL; - ret = alloc_from_pcs(s, alloc_gfp, alloc_flags, node); + ret = alloc_from_pcs(s, gfp_flags, alloc_flags, node); if (ret) goto success; @@ -5445,7 +5446,7 @@ void *_kmalloc_nolock_noprof(DECL_TOKEN_PARAMS(size, token), gfp_t gfp_flags, in * kfence_alloc. Hence call __slab_alloc_node() (at most twice) * and slab_post_alloc_hook() directly. */ - ret = __slab_alloc_node(s, alloc_gfp, node, &ac); + ret = __slab_alloc_node(s, gfp_flags, node, &ac); /* * It's possible we failed due to trylock as we preempted someone with @@ -5458,8 +5459,8 @@ void *_kmalloc_nolock_noprof(DECL_TOKEN_PARAMS(size, token), gfp_t gfp_flags, in size = s->object_size + 1; /* * Another alternative is to - * if (memcg) alloc_gfp &= ~__GFP_ACCOUNT; - * else if (!memcg) alloc_gfp |= __GFP_ACCOUNT; + * if (memcg) gfp_flags &= ~__GFP_ACCOUNT; + * else if (!memcg) gfp_flags |= __GFP_ACCOUNT; * to retry from bucket of the same size. */ can_retry = false; @@ -5468,9 +5469,9 @@ void *_kmalloc_nolock_noprof(DECL_TOKEN_PARAMS(size, token), gfp_t gfp_flags, in success: maybe_wipe_obj_freeptr(s, ret); - slab_post_alloc_hook(s, alloc_gfp, 1, &ret, &ac); + slab_post_alloc_hook(s, gfp_flags, 1, &ret, &ac); - ret = kasan_kmalloc(s, ret, orig_size, alloc_gfp); + ret = kasan_kmalloc(s, ret, orig_size, gfp_flags); return ret; } EXPORT_SYMBOL_GPL(_kmalloc_nolock_noprof); -- 2.54.0