From nobody Thu Jan 1 10:40:08 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 00578C25B47 for ; Tue, 24 Oct 2023 09:34:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234219AbjJXJel (ORCPT ); Tue, 24 Oct 2023 05:34:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40138 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234531AbjJXJeI (ORCPT ); Tue, 24 Oct 2023 05:34:08 -0400 Received: from out-206.mta0.migadu.com (out-206.mta0.migadu.com [IPv6:2001:41d0:1004:224b::ce]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 45085D7F for ; Tue, 24 Oct 2023 02:33:59 -0700 (PDT) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1698140037; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=mVsHpTi8/ybc90IBC2PUgLSTYbIjUF6GvQZHOJT0cXI=; b=WkSYYMuXGHeVTVvJKeEDkqylfQ5ISuw3VBdmhEEMq+LWy2qJeirb8he9LzRmfOp5qZ6+kT ZswKHPlHfUqDgf+oW4CzD+qBmu/0yksI5xZDpGRNHQHcev4VmDR1H8HChl9GYIrTSRecZo StPLjAgG42c97ebsxtS4Z+pyEQMwhsc= From: chengming.zhou@linux.dev To: cl@linux.com, penberg@kernel.org Cc: rientjes@google.com, iamjoonsoo.kim@lge.com, akpm@linux-foundation.org, vbabka@suse.cz, roman.gushchin@linux.dev, 42.hyeyoo@gmail.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, chengming.zhou@linux.dev, Chengming Zhou Subject: [RFC PATCH v3 1/7] slub: Keep track of whether slub is on the per-node partial list Date: Tue, 24 Oct 2023 09:33:39 +0000 Message-Id: <20231024093345.3676493-2-chengming.zhou@linux.dev> In-Reply-To: <20231024093345.3676493-1-chengming.zhou@linux.dev> References: <20231024093345.3676493-1-chengming.zhou@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Chengming Zhou Now we rely on the "frozen" bit to see if we should manipulate the slab->slab_list, which will be changed in the following patch. Instead we introduce another way to keep track of whether slub is on the per-node partial list, here we reuse the PG_workingset bit. We use __set_bit and __clear_bit directly instead of the atomic version for better performance and it's safe since it's protected by the slub node list_lock. Signed-off-by: Chengming Zhou --- mm/slab.h | 19 +++++++++++++++++++ mm/slub.c | 3 +++ 2 files changed, 22 insertions(+) diff --git a/mm/slab.h b/mm/slab.h index 8cd3294fedf5..50522b688cfb 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -193,6 +193,25 @@ static inline void __slab_clear_pfmemalloc(struct slab= *slab) __folio_clear_active(slab_folio(slab)); } =20 +/* + * Slub reuse PG_workingset bit to keep track of whether it's on + * the per-node partial list. + */ +static inline bool slab_test_node_partial(const struct slab *slab) +{ + return folio_test_workingset((struct folio *)slab_folio(slab)); +} + +static inline void slab_set_node_partial(struct slab *slab) +{ + __set_bit(PG_workingset, folio_flags(slab_folio(slab), 0)); +} + +static inline void slab_clear_node_partial(struct slab *slab) +{ + __clear_bit(PG_workingset, folio_flags(slab_folio(slab), 0)); +} + static inline void *slab_address(const struct slab *slab) { return folio_address(slab_folio(slab)); diff --git a/mm/slub.c b/mm/slub.c index 63d281dfacdb..3fad4edca34b 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -2127,6 +2127,7 @@ __add_partial(struct kmem_cache_node *n, struct slab = *slab, int tail) list_add_tail(&slab->slab_list, &n->partial); else list_add(&slab->slab_list, &n->partial); + slab_set_node_partial(slab); } =20 static inline void add_partial(struct kmem_cache_node *n, @@ -2141,6 +2142,7 @@ static inline void remove_partial(struct kmem_cache_n= ode *n, { lockdep_assert_held(&n->list_lock); list_del(&slab->slab_list); + slab_clear_node_partial(slab); n->nr_partial--; } =20 @@ -4831,6 +4833,7 @@ static int __kmem_cache_do_shrink(struct kmem_cache *= s) =20 if (free =3D=3D slab->objects) { list_move(&slab->slab_list, &discard); + slab_clear_node_partial(slab); n->nr_partial--; dec_slabs_node(s, node, slab->objects); } else if (free <=3D SHRINK_PROMOTE_MAX) --=20 2.40.1