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]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 99CC1C44503 for ; Wed, 21 Jan 2026 10:52:58 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 0A69F6B0005; Wed, 21 Jan 2026 05:52:58 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 054636B0088; Wed, 21 Jan 2026 05:52:57 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E4E226B0089; Wed, 21 Jan 2026 05:52:57 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id D36EC6B0005 for ; Wed, 21 Jan 2026 05:52:57 -0500 (EST) Received: from smtpin04.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 849B01AFB54 for ; Wed, 21 Jan 2026 10:52:57 +0000 (UTC) X-FDA: 84355658394.04.E362953 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) by imf19.hostedemail.com (Postfix) with ESMTP id 0A7C31A0005 for ; Wed, 21 Jan 2026 10:52:53 +0000 (UTC) Authentication-Results: imf19.hostedemail.com; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=wDtfqc1H; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=ds9rsOEE; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=wDtfqc1H; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=ds9rsOEE; dmarc=none; spf=pass (imf19.hostedemail.com: domain of vbabka@suse.cz designates 195.135.223.130 as permitted sender) smtp.mailfrom=vbabka@suse.cz ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1768992774; 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=3yWKsT/r92oQGsuDyaTQKStsDqOsMPpZ822IiIl7384=; b=DNXO5jyz8l7Cl+1U41Ec9qARrOu6UpQ7IFSpxUWcqTu7ARjBhMR7qvKCTGWWrsOMjH/81m xbVfdJLEtp7e2/JrccjGLOJCEyKcMY7HbOHdfZaw4w+7EOmJ7s7jb0Ib9ODwK1VbGw5n0z lqOHgSCAForQThxDn22JrSiJWJpSGw0= ARC-Authentication-Results: i=1; imf19.hostedemail.com; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=wDtfqc1H; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=ds9rsOEE; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=wDtfqc1H; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=ds9rsOEE; dmarc=none; spf=pass (imf19.hostedemail.com: domain of vbabka@suse.cz designates 195.135.223.130 as permitted sender) smtp.mailfrom=vbabka@suse.cz ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1768992774; a=rsa-sha256; cv=none; b=tjHssQ96L2Ou+wlsjHmMlV6/GK5rO3wwlRbzjHVtEcioMdFsfv1haVsPAcJJ+8M2qervjq 3ehq/qFn8xDwNnL3lGP26M0w2emWFNfS6d2ZPrHa/aEOZKdQbJcBcsq7mLahhWqX0iKA6/ i1rWx/D+Z7czUc1pYVvVL6738SFHwGI= Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [IPv6:2a07:de40:b281:104:10:150:64:97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id F128933689; Wed, 21 Jan 2026 10:52:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1768992772; h=from:from:reply-to: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:autocrypt:autocrypt; bh=3yWKsT/r92oQGsuDyaTQKStsDqOsMPpZ822IiIl7384=; b=wDtfqc1HX9yH9IqQqXc2lZX8pjG8EU4+Z4WymKfo0WY0E7P9spxk7Dp8EcKMmJ29H/eagu 3UgfeyUbEaPJJ19g7AVCn4QGiJ/bTDmtOMiiawlDEE/a4BmPWgJipb6ywrR180DzlxIRw9 oMhgv74qH0+IelJMqOEo1EsZbpdaP7I= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1768992772; h=from:from:reply-to: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:autocrypt:autocrypt; bh=3yWKsT/r92oQGsuDyaTQKStsDqOsMPpZ822IiIl7384=; b=ds9rsOEE6HJU/NSclYnOPDW7KodllO96FHGYeSpqgwnyUxDEzXkveHQDmNOiR2czUDkUzD sk7pVW98DIDRvaDg== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1768992772; h=from:from:reply-to: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:autocrypt:autocrypt; bh=3yWKsT/r92oQGsuDyaTQKStsDqOsMPpZ822IiIl7384=; b=wDtfqc1HX9yH9IqQqXc2lZX8pjG8EU4+Z4WymKfo0WY0E7P9spxk7Dp8EcKMmJ29H/eagu 3UgfeyUbEaPJJ19g7AVCn4QGiJ/bTDmtOMiiawlDEE/a4BmPWgJipb6ywrR180DzlxIRw9 oMhgv74qH0+IelJMqOEo1EsZbpdaP7I= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1768992772; h=from:from:reply-to: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:autocrypt:autocrypt; bh=3yWKsT/r92oQGsuDyaTQKStsDqOsMPpZ822IiIl7384=; b=ds9rsOEE6HJU/NSclYnOPDW7KodllO96FHGYeSpqgwnyUxDEzXkveHQDmNOiR2czUDkUzD sk7pVW98DIDRvaDg== Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id C49DC3EA63; Wed, 21 Jan 2026 10:52:51 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id 9h+wLwOwcGkYEwAAD6G6ig (envelope-from ); Wed, 21 Jan 2026 10:52:51 +0000 Message-ID: Date: Wed, 21 Jan 2026 11:52:51 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 06/21] slab: introduce percpu sheaves bootstrap Content-Language: en-US To: Suren Baghdasaryan Cc: Harry Yoo , Petr Tesarik , Christoph Lameter , David Rientjes , Roman Gushchin , Hao Li , Andrew Morton , Uladzislau Rezki , "Liam R. Howlett" , Sebastian Andrzej Siewior , Alexei Starovoitov , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-rt-devel@lists.linux.dev, bpf@vger.kernel.org, kasan-dev@googlegroups.com References: <20260116-sheaves-for-all-v3-0-5595cb000772@suse.cz> <20260116-sheaves-for-all-v3-6-5595cb000772@suse.cz> From: Vlastimil Babka Autocrypt: addr=vbabka@suse.cz; keydata= xsFNBFZdmxYBEADsw/SiUSjB0dM+vSh95UkgcHjzEVBlby/Fg+g42O7LAEkCYXi/vvq31JTB KxRWDHX0R2tgpFDXHnzZcQywawu8eSq0LxzxFNYMvtB7sV1pxYwej2qx9B75qW2plBs+7+YB 87tMFA+u+L4Z5xAzIimfLD5EKC56kJ1CsXlM8S/LHcmdD9Ctkn3trYDNnat0eoAcfPIP2OZ+ 9oe9IF/R28zmh0ifLXyJQQz5ofdj4bPf8ecEW0rhcqHfTD8k4yK0xxt3xW+6Exqp9n9bydiy tcSAw/TahjW6yrA+6JhSBv1v2tIm+itQc073zjSX8OFL51qQVzRFr7H2UQG33lw2QrvHRXqD Ot7ViKam7v0Ho9wEWiQOOZlHItOOXFphWb2yq3nzrKe45oWoSgkxKb97MVsQ+q2SYjJRBBH4 8qKhphADYxkIP6yut/eaj9ImvRUZZRi0DTc8xfnvHGTjKbJzC2xpFcY0DQbZzuwsIZ8OPJCc LM4S7mT25NE5kUTG/TKQCk922vRdGVMoLA7dIQrgXnRXtyT61sg8PG4wcfOnuWf8577aXP1x 6mzw3/jh3F+oSBHb/GcLC7mvWreJifUL2gEdssGfXhGWBo6zLS3qhgtwjay0Jl+kza1lo+Cv BB2T79D4WGdDuVa4eOrQ02TxqGN7G0Biz5ZLRSFzQSQwLn8fbwARAQABzSBWbGFzdGltaWwg QmFia2EgPHZiYWJrYUBzdXNlLmN6PsLBlAQTAQoAPgIbAwULCQgHAwUVCgkICwUWAgMBAAIe AQIXgBYhBKlA1DSZLC6OmRA9UCJPp+fMgqZkBQJnyBr8BQka0IFQAAoJECJPp+fMgqZkqmMQ AIbGN95ptUMUvo6aAdhxaOCHXp1DfIBuIOK/zpx8ylY4pOwu3GRe4dQ8u4XS9gaZ96Gj4bC+ jwWcSmn+TjtKW3rH1dRKopvC07tSJIGGVyw7ieV/5cbFffA8NL0ILowzVg8w1ipnz1VTkWDr 2zcfslxJsJ6vhXw5/npcY0ldeC1E8f6UUoa4eyoskd70vO0wOAoGd02ZkJoox3F5ODM0kjHu Y97VLOa3GG66lh+ZEelVZEujHfKceCw9G3PMvEzyLFbXvSOigZQMdKzQ8D/OChwqig8wFBmV QCPS4yDdmZP3oeDHRjJ9jvMUKoYODiNKsl2F+xXwyRM2qoKRqFlhCn4usVd1+wmv9iLV8nPs 2Db1ZIa49fJet3Sk3PN4bV1rAPuWvtbuTBN39Q/6MgkLTYHb84HyFKw14Rqe5YorrBLbF3rl M51Dpf6Egu1yTJDHCTEwePWug4XI11FT8lK0LNnHNpbhTCYRjX73iWOnFraJNcURld1jL1nV r/LRD+/e2gNtSTPK0Qkon6HcOBZnxRoqtazTU6YQRmGlT0v+rukj/cn5sToYibWLn+RoV1CE Qj6tApOiHBkpEsCzHGu+iDQ1WT0Idtdynst738f/uCeCMkdRu4WMZjteQaqvARFwCy3P/jpK uvzMtves5HvZw33ZwOtMCgbpce00DaET4y/UzsBNBFsZNTUBCACfQfpSsWJZyi+SHoRdVyX5 J6rI7okc4+b571a7RXD5UhS9dlVRVVAtrU9ANSLqPTQKGVxHrqD39XSw8hxK61pw8p90pg4G /N3iuWEvyt+t0SxDDkClnGsDyRhlUyEWYFEoBrrCizbmahOUwqkJbNMfzj5Y7n7OIJOxNRkB IBOjPdF26dMP69BwePQao1M8Acrrex9sAHYjQGyVmReRjVEtv9iG4DoTsnIR3amKVk6si4Ea X/mrapJqSCcBUVYUFH8M7bsm4CSxier5ofy8jTEa/CfvkqpKThTMCQPNZKY7hke5qEq1CBk2 wxhX48ZrJEFf1v3NuV3OimgsF2odzieNABEBAAHCwXwEGAEKACYCGwwWIQSpQNQ0mSwujpkQ PVAiT6fnzIKmZAUCZ8gcVAUJFhTonwAKCRAiT6fnzIKmZLY8D/9uo3Ut9yi2YCuASWxr7QQZ lJCViArjymbxYB5NdOeC50/0gnhK4pgdHlE2MdwF6o34x7TPFGpjNFvycZqccSQPJ/gibwNA zx3q9vJT4Vw+YbiyS53iSBLXMweeVV1Jd9IjAoL+EqB0cbxoFXvnjkvP1foiiF5r73jCd4PR rD+GoX5BZ7AZmFYmuJYBm28STM2NA6LhT0X+2su16f/HtummENKcMwom0hNu3MBNPUOrujtW khQrWcJNAAsy4yMoJ2Lw51T/5X5Hc7jQ9da9fyqu+phqlVtn70qpPvgWy4HRhr25fCAEXZDp xG4RNmTm+pqorHOqhBkI7wA7P/nyPo7ZEc3L+ZkQ37u0nlOyrjbNUniPGxPxv1imVq8IyycG AN5FaFxtiELK22gvudghLJaDiRBhn8/AhXc642/Z/yIpizE2xG4KU4AXzb6C+o7LX/WmmsWP Ly6jamSg6tvrdo4/e87lUedEqCtrp2o1xpn5zongf6cQkaLZKQcBQnPmgHO5OG8+50u88D9I rywqgzTUhHFKKF6/9L/lYtrNcHU8Z6Y4Ju/MLUiNYkmtrGIMnkjKCiRqlRrZE/v5YFHbayRD dJKXobXTtCBYpLJM4ZYRpGZXne/FAtWNe4KbNJJqxMvrTOrnIatPj8NhBVI0RSJRsbilh6TE m6M14QORSWTLRg== In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Action: no action X-Rspam-User: X-Rspamd-Queue-Id: 0A7C31A0005 X-Rspamd-Server: rspam11 X-Stat-Signature: rjfq3o5xneaw94d6e8i3xtwb53f7uszu X-HE-Tag: 1768992773-845884 X-HE-Meta: U2FsdGVkX1/MuIQMiXGZBjxXX5ccA1JGvRFluM7qsJiqejgXDyyfjoI6EVYWFzFE24vIu4bZRBZWCoiAQcxQmFVgwA1kV94CZBPk/gcCOa+amCCgz/bvCClZwKyyU/nxXCDSoz1VZuFtKPPsR1oLqZ9ZoC1D7t6Lcd6DPO8BJMsqcmzGM42Gl0fuHdL1c5zVFpyLdY5c7ElPioeethinbKqABhOMFZE/U1Say2dq660tnfddtgSFWlhXss97jh5S3tddmvHx3+DnhJEC8A3RAtQDpgKXGc6umLwd5p4jmh0DmxFbS/BrVcYJn5Iexix6pAPlFnW6yfdhNZ1xizVDrHEFDOJjm8ergn537onCJDn90I1OqkJzUWMWqbCIkKtfSsvAoKSC9PWM86Hd7R2IbBerBnDHT8yjm5Ym3LNu+xFG3LiOfDWRrXu20qLtyL27hWozbro6cLeqH/kMV+D9tAtWtZYrcBmEHYrA7ZHgsEkCvtTBogGSAi6WY3aSXtQD1BLM4sB8a7sCut2rW5LRSpW1rOmO+d5bG6QCrTo0p/ZJbj0ql/we6wyJBMslq3qzsL7jtu8tmv7iOGX3z7MrZVGhMm9b4rtkyrditU2eNuWJqnXjNgT65TDKre0q2RcgLjQVRZhVIXCu8I2zWe6xJmbWidGYS+mQLHlpidKp/4TwgJelvkkuH1WW0HbsIWNP+PedHXOrE4b0QT9TususYeQHgep/ubTDQ7JGIDAsts9fzkfrA/tV3lMsRy728AVkXeybrlH+4vld0W8WRoTvdBq6Pb1A4a/YP9o8RqWeZ/AQPeLnBgVxV9mexj8Q5WXwZL5a7StIIM9C+53MGt49oGlCsBLp+VnZ3Hgqd21F54v3OUR3vlIKXGkECHgVwmqaoM97MHpShtCQtgkOb86cK8cK9aLyEScPxEskgPwVjRYTQmRSn8dAFDCsXBFuJwj0Q5wEOU8nBrAfkLgfazb YbcdlMT7 iDZGngsHdIWDHrp400kXrRSpxwXdVHUvtNjuuQ69BP4NjBF+uz1wQVhl7ocobDPYeUEGUkGkQwK68tqPCEsbKlNdS63xO0jux70CRjYymmTqZHae25blN3mwEzzXSaCHp5moHOGFjxiPaOGf5xkKDedeEoPHX9hbXQ/8mi5236zqSuzaFRCTUKoF2P48uT6PkA5vX8NGH8z+QBH+2GtMKDECIJQox2Xo+ArzZosCqjYJp5ILXNr2wOwuOidUvpy/9VCPI2zop/a9uwK/6QzRn8c0XYKgSOXBxDE+9 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 1/17/26 03:11, Suren Baghdasaryan wrote: >> @@ -7379,7 +7405,7 @@ void kmem_cache_free_bulk(struct kmem_cache *s, size_t size, void **p) >> * freeing to sheaves is so incompatible with the detached freelist so >> * once we go that way, we have to do everything differently >> */ >> - if (s && s->cpu_sheaves) { >> + if (s && cache_has_sheaves(s)) { >> free_to_pcs_bulk(s, size, p); >> return; >> } >> @@ -7490,8 +7516,7 @@ int kmem_cache_alloc_bulk_noprof(struct kmem_cache *s, gfp_t flags, size_t size, >> size--; >> } >> >> - if (s->cpu_sheaves) >> - i = alloc_from_pcs_bulk(s, size, p); >> + i = alloc_from_pcs_bulk(s, size, p); > > Doesn't the above change make this fastpath a bit longer? IIUC, > instead of bailing out right here we call alloc_from_pcs_bulk() and > bail out from there because pcs->main->size is 0. But only for caches with no sheaves, and that should be the exception. So the fast path avoids checks. We're making the slowpath longer. The strategy is the same with single-object alloc, and described in the changelog. Or what am I missing?