From mboxrd@z Thu Jan 1 00:00:00 1970 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4000EC4167B for ; Sun, 3 Dec 2023 09:47:30 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 866B76B02F7; Sun, 3 Dec 2023 04:47:29 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 816F86B0303; Sun, 3 Dec 2023 04:47:29 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 706A36B0305; Sun, 3 Dec 2023 04:47:29 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 629A66B02F7 for ; Sun, 3 Dec 2023 04:47:29 -0500 (EST) Received: from smtpin18.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 28178C0248 for ; Sun, 3 Dec 2023 09:47:29 +0000 (UTC) X-FDA: 81525029418.18.9230709 Received: from mail-il1-f176.google.com (mail-il1-f176.google.com [209.85.166.176]) by imf19.hostedemail.com (Postfix) with ESMTP id 5417E1A000F for ; Sun, 3 Dec 2023 09:47:27 +0000 (UTC) Authentication-Results: imf19.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=XS3TKpgj; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf19.hostedemail.com: domain of 42.hyeyoo@gmail.com designates 209.85.166.176 as permitted sender) smtp.mailfrom=42.hyeyoo@gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1701596847; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=S+bxWhgSrWR9hNjabL8i2+0TzMETPf1z+GLfNoJ9zJ8=; b=RjyEKKxkSoTnQoRZoJMzpn7cNpiSATYpIwtlJoJYpIu0qTPqZAT+ZJnNxoGRhJJ10SXps0 yGYpJTuhMgY0rlPGWb34PO8dULk57JkytUbEk1yilJj9YhsHoaU+oSW5pWHMj4P+jR5a/n TR5Uz2Rog/Jit1oSfQ6VjwU2u9hGfq8= ARC-Authentication-Results: i=1; imf19.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=XS3TKpgj; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf19.hostedemail.com: domain of 42.hyeyoo@gmail.com designates 209.85.166.176 as permitted sender) smtp.mailfrom=42.hyeyoo@gmail.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1701596847; a=rsa-sha256; cv=none; b=c7K65NpgpOYWweCCfBLQdjm5zh9ji5uu9CnE64wvHVAImvi5aPcQQzXfVgguvxKvu5aZ+t O4xYBc18vgMra66oLRcvhM5bOky7RE3ItcIE1LPl28J1cI1MnpDJ/qsm0fWClc3Do3syML akhIuLsjIsfm8J0yjdqznhXrF1Vxx8E= Received: by mail-il1-f176.google.com with SMTP id e9e14a558f8ab-35d4de84195so10067655ab.3 for ; Sun, 03 Dec 2023 01:47:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1701596846; x=1702201646; darn=kvack.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=S+bxWhgSrWR9hNjabL8i2+0TzMETPf1z+GLfNoJ9zJ8=; b=XS3TKpgjHwGxj91UpXzydeDTMQCcYQCcrb5nN1ddmtaZ5a3zm0PU7pRTLrwHCrOpYm mJBX9oaAWqQWOG04nON86hdYkEDjfqsZ+m7zh6q/8KhWDXPH2OoRhSfcW3Eih7rvIJuv LLlvxGHPi/rWoQhV5z96ES2cFH3o38kaL0+bWimYcihJJfrPshp48TEZgZHBhXl2nIn0 jYxXvQ8xtxWniwy8RGu8pUNlxI4SMqqJve8BTdH0OFCiRKdpGxsC83ndbV18pl7wKyhn VFS8BrevHDkMZFswkoKRPXTHbEo5hye4rIUTf2CT/zHD+z6Powo+DXXjBnc5vUxTyLY4 xg+w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701596846; x=1702201646; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=S+bxWhgSrWR9hNjabL8i2+0TzMETPf1z+GLfNoJ9zJ8=; b=A2ShHkDtWaEV+pmHnOnDUigQac2GsuUuvYahVYGNvewArEg8W/jTtkzEcjTJ/fI6Z+ 4OSkFqRjWG0J2PbM+jU2RKn4Mrs/o5UdJYuROaDnpcTigM8TtfJ/OgdCr+yG8c6BwuW5 pEWsTEFZ+4H3C0zlP9xB/1KelfnzFpi7W1U1W9wgm6tkrdjKUkLK2z3vb2mIGGKrAK7J C4fNd7R1+VdWrQTpDNJMdaLyqQtrncB+SqEISLFYV2j43f8DJed5GWlwywitfRuVAQgb M2/cTfc4s8W9r6fP/P2GtwJEjqGL60j5q+fKv28q0YfakKdvzgYZapX3Tr3kLAzIVrhV pejg== X-Gm-Message-State: AOJu0YyKjWQmQ5nvwk/tmKUFeBTdL64RFkI5CHcdG5NaLmIe0bnvudzX V4mX7dagXec04M0dFqeNncpX4nQPQTL5J6fyJAk= X-Google-Smtp-Source: AGHT+IEB/MI2aa8cbaWymUflduhtaIGxonyyFw5LGSLaYQe49fEL0UrklcHthFdspyx2nGEx+8X3DkiuyCC9RkT7rfc= X-Received: by 2002:a92:ce05:0:b0:35d:6227:4efc with SMTP id b5-20020a92ce05000000b0035d62274efcmr1392700ilo.57.1701596846435; Sun, 03 Dec 2023 01:47:26 -0800 (PST) MIME-Version: 1.0 References: <20231102032330.1036151-1-chengming.zhou@linux.dev> <20231102032330.1036151-10-chengming.zhou@linux.dev> In-Reply-To: <20231102032330.1036151-10-chengming.zhou@linux.dev> From: Hyeonggon Yoo <42.hyeyoo@gmail.com> Date: Sun, 3 Dec 2023 18:47:14 +0900 Message-ID: Subject: Re: [PATCH v5 9/9] slub: Update frozen slabs documentations in the source To: chengming.zhou@linux.dev Cc: vbabka@suse.cz, cl@linux.com, penberg@kernel.org, rientjes@google.com, iamjoonsoo.kim@lge.com, akpm@linux-foundation.org, roman.gushchin@linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Chengming Zhou Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspam-User: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 5417E1A000F X-Stat-Signature: 9dsg9b35snemw8qdnbfxmxnyuidka1z9 X-HE-Tag: 1701596847-243308 X-HE-Meta: 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 tI3d4hPC Bf/xLDK3/f3FUA8oXf/pMpproQEa0/e+CLFwp4ZUxg5a4/SJqx8FphkRBHHmbMkouFzvig7xsqTMUU/5NvN4ubewtkc/ZyS1seqnTJVd224/5B4e7lIFZ0vxq34ktkluS0M4wcZqFhZJlJ1BGr4et8l6XTRoay3Ohrw9ESlVrK0DcQy/TH0AycfU5ZBuIG4lYebtJna7wiosQldK/uZ6dDdn7gPl4tRAWUiNJqhNssSc20zvjWIrto5Tn3GTIdlzu8suluYeaJxkwMQXYEtrOOrgw7NhxNfRTf/KxmH2S6PQFnoMc3V/OiaLb8dpwSiLQtHVx4YXzskctOEvvyOrQecxJtieodgxTFxLpHeiR9uaMJJ4FXtqk4D3g8poSzFKSdMsEs5ckgDQHcCz2nK3tD6d18/erSV7s8dN41pNr6Tr/pEep86sCPpkdzi460kN5mjjx0kVzv2XRddur1fP9vWrO3Q== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, Nov 2, 2023 at 12:25=E2=80=AFPM wrote: > > From: Chengming Zhou > > The current updated scheme (which this series implemented) is: > - node partial slabs: PG_Workingset && !frozen > - cpu partial slabs: !PG_Workingset && !frozen > - cpu slabs: !PG_Workingset && frozen > - full slabs: !PG_Workingset && !frozen > > The most important change is that "frozen" bit is not set for the > cpu partial slabs anymore, __slab_free() will grab node list_lock > then check by !PG_Workingset that it's not on a node partial list. > > And the "frozen" bit is still kept for the cpu slabs for performance, > since we don't need to grab node list_lock to check whether the > PG_Workingset is set or not if the "frozen" bit is set in __slab_free(). > > Update related documentations and comments in the source. > > Signed-off-by: Chengming Zhou > Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> > --- > mm/slub.c | 16 ++++++++++++---- > 1 file changed, 12 insertions(+), 4 deletions(-) > > diff --git a/mm/slub.c b/mm/slub.c > index c20bdf5dab0f..a307d319e82c 100644 > --- a/mm/slub.c > +++ b/mm/slub.c > @@ -76,13 +76,22 @@ > * > * Frozen slabs > * > - * If a slab is frozen then it is exempt from list management. It is n= ot > - * on any list except per cpu partial list. The processor that froze t= he > + * If a slab is frozen then it is exempt from list management. It is > + * the cpu slab which is actively allocated from by the processor that > + * froze it and it is not on any list. The processor that froze the > * slab is the one who can perform list operations on the slab. Other > * processors may put objects onto the freelist but the processor that > * froze the slab is the only one that can retrieve the objects from t= he > * slab's freelist. > * > + * CPU partial slabs > + * > + * The partially empty slabs cached on the CPU partial list are used > + * for performance reasons, which speeds up the allocation process. > + * These slabs are not frozen, but are also exempt from list managemen= t, > + * by clearing the PG_workingset flag when moving out of the node > + * partial list. Please see __slab_free() for more details. > + * > * list_lock > * > * The list_lock protects the partial and full list on each node and > @@ -2617,8 +2626,7 @@ static void put_partials_cpu(struct kmem_cache *s, > } > > /* > - * Put a slab that was just frozen (in __slab_free|get_partial_node) int= o a > - * partial slab slot if available. > + * Put a slab into a partial slab slot if available. > * > * If we did not find a slot then simply move all the partials to the > * per node partial list. > -- Looks good to me, Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Thanks! > 2.20.1 >