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 3E673D32D82 for ; Tue, 12 Nov 2024 10:07:26 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id BE9226B0099; Tue, 12 Nov 2024 05:07:25 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id B957C6B00CA; Tue, 12 Nov 2024 05:07:25 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9C1456B00CC; Tue, 12 Nov 2024 05:07:25 -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 7C2376B0099 for ; Tue, 12 Nov 2024 05:07:25 -0500 (EST) Received: from smtpin21.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 33F26120F89 for ; Tue, 12 Nov 2024 10:07:25 +0000 (UTC) X-FDA: 82777014306.21.E0F36D7 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) by imf28.hostedemail.com (Postfix) with ESMTP id 38E73C0016 for ; Tue, 12 Nov 2024 10:06:40 +0000 (UTC) Authentication-Results: imf28.hostedemail.com; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=M47x6GJ0; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=0IoXzgLp; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=M47x6GJ0; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=0IoXzgLp; spf=pass (imf28.hostedemail.com: domain of vbabka@suse.cz designates 195.135.223.130 as permitted sender) smtp.mailfrom=vbabka@suse.cz; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1731405870; 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=MGDm23N0btDZ/ygxqDfjW8gUuYa5kE9YjORkIqBxqzA=; b=I04/ju4gonuwfk51qNEEDcr6XCmxwvu5oD+KJEvV98F43WalD6t+tju1FEcQPD51LKE5kX B9pkLIAovYNpoOG7hvFPW7MzEcpSQ007mpGbiDm/m5Oj9BgWNu4BYbvwRAKOd8E3VCIj5q lnr+R41hwAZN3+5C/u0Y9z94Q7aQMV0= ARC-Authentication-Results: i=1; imf28.hostedemail.com; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=M47x6GJ0; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=0IoXzgLp; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=M47x6GJ0; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=0IoXzgLp; spf=pass (imf28.hostedemail.com: domain of vbabka@suse.cz designates 195.135.223.130 as permitted sender) smtp.mailfrom=vbabka@suse.cz; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1731405870; a=rsa-sha256; cv=none; b=NVjCner6x2flfiH+Jcmv4NkzxmzoxEhLuD2GLnMZGS+1zX6CA68KC30oGosNqGShK8/qDi tG5mcVJIYSfkd8HUMjNQDektZTfBiT0Y6Q9aO0wtvQiJVcvTjLnx7fdqNogpLJkBv5ijgd CjZJECn+8aRJcquz15OJ1+ZdOAaT5Q4= 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 B0924216E7; Tue, 12 Nov 2024 10:07:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1731406040; 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=MGDm23N0btDZ/ygxqDfjW8gUuYa5kE9YjORkIqBxqzA=; b=M47x6GJ0LX05abHbQdWGDM2MWjTN+Jztt9caSXg99IKDX78+lkaCDrJG9XeWxLFqgy8Ifl 7pLxtVgCh3EKEQwGYTTD3a7cVd3LQszvaxvmvqpq3pao7+ndJDnbv2iHeA6LC+qDQzqgSC Sehmv9uy6mXiYHyvn3obN5FmMCUoeYk= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1731406040; 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=MGDm23N0btDZ/ygxqDfjW8gUuYa5kE9YjORkIqBxqzA=; b=0IoXzgLpUuWCn+6zmz/RZiQPxlO22yMl1CstCYbds7ClRMtt6ALB9X5DDEhBz9eU7802M3 ZBspoBbEFOtzFoCA== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1731406040; 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=MGDm23N0btDZ/ygxqDfjW8gUuYa5kE9YjORkIqBxqzA=; b=M47x6GJ0LX05abHbQdWGDM2MWjTN+Jztt9caSXg99IKDX78+lkaCDrJG9XeWxLFqgy8Ifl 7pLxtVgCh3EKEQwGYTTD3a7cVd3LQszvaxvmvqpq3pao7+ndJDnbv2iHeA6LC+qDQzqgSC Sehmv9uy6mXiYHyvn3obN5FmMCUoeYk= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1731406040; 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=MGDm23N0btDZ/ygxqDfjW8gUuYa5kE9YjORkIqBxqzA=; b=0IoXzgLpUuWCn+6zmz/RZiQPxlO22yMl1CstCYbds7ClRMtt6ALB9X5DDEhBz9eU7802M3 ZBspoBbEFOtzFoCA== 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 789E213721; Tue, 12 Nov 2024 10:07:20 +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 rgD3HNgoM2fTKgAAD6G6ig (envelope-from ); Tue, 12 Nov 2024 10:07:20 +0000 Message-ID: Date: Tue, 12 Nov 2024 11:07:20 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 4/4] mm: move lesser used vma_area_struct members into the last cacheline Content-Language: en-US To: Suren Baghdasaryan , akpm@linux-foundation.org Cc: willy@infradead.org, liam.howlett@oracle.com, lorenzo.stoakes@oracle.com, mhocko@suse.com, hannes@cmpxchg.org, mjguzik@gmail.com, oliver.sang@intel.com, mgorman@techsingularity.net, david@redhat.com, peterx@redhat.com, oleg@redhat.com, dave@stgolabs.net, paulmck@kernel.org, brauner@kernel.org, dhowells@redhat.com, hdanton@sina.com, hughd@google.com, minchan@google.com, jannh@google.com, shakeel.butt@linux.dev, souravpanda@google.com, pasha.tatashin@soleen.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@android.com References: <20241111205506.3404479-1-surenb@google.com> <20241111205506.3404479-5-surenb@google.com> 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+fMgqZkBQJkBREIBQkRadznAAoJECJPp+fMgqZkNxIQ ALZRqwdUGzqL2aeSavbum/VF/+td+nZfuH0xeWiO2w8mG0+nPd5j9ujYeHcUP1edE7uQrjOC Gs9sm8+W1xYnbClMJTsXiAV88D2btFUdU1mCXURAL9wWZ8Jsmz5ZH2V6AUszvNezsS/VIT87 AmTtj31TLDGwdxaZTSYLwAOOOtyqafOEq+gJB30RxTRE3h3G1zpO7OM9K6ysLdAlwAGYWgJJ V4JqGsQ/lyEtxxFpUCjb5Pztp7cQxhlkil0oBYHkudiG8j1U3DG8iC6rnB4yJaLphKx57NuQ PIY0Bccg+r9gIQ4XeSK2PQhdXdy3UWBr913ZQ9AI2usid3s5vabo4iBvpJNFLgUmxFnr73SJ KsRh/2OBsg1XXF/wRQGBO9vRuJUAbnaIVcmGOUogdBVS9Sun/Sy4GNA++KtFZK95U7J417/J Hub2xV6Ehc7UGW6fIvIQmzJ3zaTEfuriU1P8ayfddrAgZb25JnOW7L1zdYL8rXiezOyYZ8Fm ZyXjzWdO0RpxcUEp6GsJr11Bc4F3aae9OZtwtLL/jxc7y6pUugB00PodgnQ6CMcfR/HjXlae h2VS3zl9+tQWHu6s1R58t5BuMS2FNA58wU/IazImc/ZQA+slDBfhRDGYlExjg19UXWe/gMcl De3P1kxYPgZdGE2eZpRLIbt+rYnqQKy8UxlszsBNBFsZNTUBCACfQfpSsWJZyi+SHoRdVyX5 J6rI7okc4+b571a7RXD5UhS9dlVRVVAtrU9ANSLqPTQKGVxHrqD39XSw8hxK61pw8p90pg4G /N3iuWEvyt+t0SxDDkClnGsDyRhlUyEWYFEoBrrCizbmahOUwqkJbNMfzj5Y7n7OIJOxNRkB IBOjPdF26dMP69BwePQao1M8Acrrex9sAHYjQGyVmReRjVEtv9iG4DoTsnIR3amKVk6si4Ea X/mrapJqSCcBUVYUFH8M7bsm4CSxier5ofy8jTEa/CfvkqpKThTMCQPNZKY7hke5qEq1CBk2 wxhX48ZrJEFf1v3NuV3OimgsF2odzieNABEBAAHCwXwEGAEKACYCGwwWIQSpQNQ0mSwujpkQ PVAiT6fnzIKmZAUCZAUSmwUJDK5EZgAKCRAiT6fnzIKmZOJGEACOKABgo9wJXsbWhGWYO7mD 8R8mUyJHqbvaz+yTLnvRwfe/VwafFfDMx5GYVYzMY9TWpA8psFTKTUIIQmx2scYsRBUwm5VI EurRWKqENcDRjyo+ol59j0FViYysjQQeobXBDDE31t5SBg++veI6tXfpco/UiKEsDswL1WAr tEAZaruo7254TyH+gydURl2wJuzo/aZ7Y7PpqaODbYv727Dvm5eX64HCyyAH0s6sOCyGF5/p eIhrOn24oBf67KtdAN3H9JoFNUVTYJc1VJU3R1JtVdgwEdr+NEciEfYl0O19VpLE/PZxP4wX PWnhf5WjdoNI1Xec+RcJ5p/pSel0jnvBX8L2cmniYnmI883NhtGZsEWj++wyKiS4NranDFlA HdDM3b4lUth1pTtABKQ1YuTvehj7EfoWD3bv9kuGZGPrAeFNiHPdOT7DaXKeHpW9homgtBxj 8aX/UkSvEGJKUEbFL9cVa5tzyialGkSiZJNkWgeHe+jEcfRT6pJZOJidSCdzvJpbdJmm+eED w9XOLH1IIWh7RURU7G1iOfEfmImFeC3cbbS73LQEFGe1urxvIH5K/7vX+FkNcr9ujwWuPE9b 1C2o4i/yZPLXIVy387EjA6GZMqvQUFuSTs/GeBcv0NjIQi8867H3uLjz+mQy63fAitsDwLmR EP+ylKVEKb0Q2A== In-Reply-To: <20241111205506.3404479-5-surenb@google.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Action: no action X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 38E73C0016 X-Stat-Signature: 589toijw4cwq7wdw15jjkhyw4zkx99cg X-Rspam-User: X-HE-Tag: 1731406000-510129 X-HE-Meta: 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 XiC9WmoS Wd9JAizKHEEhwaJ2fguAtsI0ys9SHYbnKi8pffZZvDYpo0JtRO3doYOan2mpJc2SRtIrR4q3qEco79dTir75Z+Q7ajjUS/klSMa8J1jYhxJchhJ6O8DF35uc1lKtDB6LUFRRgVNTmDkHwFxWtPJAp7xBYKxfgNf4hY2As2ZhzSsWazbRuHHopj90upAZo6htlxDWG9IiLKnLmqdmliWvdgIMWLBDPAPvzrmGBG2jYoixr8+lxGXCHCYXRXOrTs+3+IBReBKajGke32hkWMv5XpktNsL6Skl8uDciMH995c0Gr+VjohmQDJzI5LSxBlpNK5NrIHp3vmhxCvNUm4kJj85kwy9L3wNwGe0j4pxkJCnTiuho= 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 11/11/24 21:55, Suren Baghdasaryan wrote: > Move several vma_area_struct members which are rarely or never used > during page fault handling into the last cacheline to better pack > vm_area_struct. As a result vm_area_struct will fit into 3 cachelines > as opposed to 4 cachelines before this change. New vm_area_struct layout: > > struct vm_area_struct { > union { > struct { > long unsigned int vm_start; /* 0 8 */ > long unsigned int vm_end; /* 8 8 */ > }; /* 0 16 */ > struct callback_head vm_rcu ; /* 0 16 */ > } __attribute__((__aligned__(8))); /* 0 16 */ > struct mm_struct * vm_mm; /* 16 8 */ > pgprot_t vm_page_prot; /* 24 8 */ > union { > const vm_flags_t vm_flags; /* 32 8 */ > vm_flags_t __vm_flags; /* 32 8 */ > }; /* 32 8 */ > bool detached; /* 40 1 */ > > /* XXX 3 bytes hole, try to pack */ > > unsigned int vm_lock_seq; /* 44 4 */ > struct list_head anon_vma_chain; /* 48 16 */ > /* --- cacheline 1 boundary (64 bytes) --- */ > struct anon_vma * anon_vma; /* 64 8 */ > const struct vm_operations_struct * vm_ops; /* 72 8 */ > long unsigned int vm_pgoff; /* 80 8 */ > struct file * vm_file; /* 88 8 */ > void * vm_private_data; /* 96 8 */ > atomic_long_t swap_readahead_info; /* 104 8 */ > struct mempolicy * vm_policy; /* 112 8 */ > > /* XXX 8 bytes hole, try to pack */ > > /* --- cacheline 2 boundary (128 bytes) --- */ > struct vma_lock vm_lock (__aligned__(64)); /* 128 4 */ > > /* XXX 4 bytes hole, try to pack */ > > struct { > struct rb_node rb (__aligned__(8)); /* 136 24 */ > long unsigned int rb_subtree_last; /* 160 8 */ > } __attribute__((__aligned__(8))) shared; /* 136 32 */ > struct vm_userfaultfd_ctx vm_userfaultfd_ctx; /* 168 0 */ I don't see anon_name in the output, I thought it was added for Android? :) > > /* size: 192, cachelines: 3, members: 17 */ > /* sum members: 153, holes: 3, sum holes: 15 */ > /* padding: 24 */ Instead you seem to have padding so an attempt to use SLAB_TYPESAFE_BY_RCU should use that and not add more up to 256 pages. Perhaps this pahole output wasn't generated with a fully representative config? > /* forced alignments: 3, forced holes: 2, sum forced holes: 12 */ > } __attribute__((__aligned__(64))); > > > Memory consumption per 1000 VMAs becomes 48 pages: > > slabinfo after vm_area_struct changes: > ... : ... > vm_area_struct ... 192 42 2 : ... > > > Signed-off-by: Suren Baghdasaryan > --- > include/linux/mm_types.h | 37 ++++++++++++++++++------------------- > 1 file changed, 18 insertions(+), 19 deletions(-) > > diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h > index 789bccc05520..c3755b680911 100644 > --- a/include/linux/mm_types.h > +++ b/include/linux/mm_types.h > @@ -733,16 +733,6 @@ struct vm_area_struct { > unsigned int vm_lock_seq; > #endif > > - /* > - * For areas with an address space and backing store, > - * linkage into the address_space->i_mmap interval tree. > - * > - */ > - struct { > - struct rb_node rb; > - unsigned long rb_subtree_last; > - } shared; > - > /* > * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma > * list, after a COW of one of the file pages. A MAP_SHARED vma > @@ -762,14 +752,6 @@ struct vm_area_struct { > struct file * vm_file; /* File we map to (can be NULL). */ > void * vm_private_data; /* was vm_pte (shared mem) */ > > -#ifdef CONFIG_ANON_VMA_NAME > - /* > - * For private and shared anonymous mappings, a pointer to a null > - * terminated string containing the name given to the vma, or NULL if > - * unnamed. Serialized by mmap_lock. Use anon_vma_name to access. > - */ > - struct anon_vma_name *anon_name; > -#endif > #ifdef CONFIG_SWAP > atomic_long_t swap_readahead_info; > #endif > @@ -782,11 +764,28 @@ struct vm_area_struct { > #ifdef CONFIG_NUMA_BALANCING > struct vma_numab_state *numab_state; /* NUMA Balancing state */ > #endif > - struct vm_userfaultfd_ctx vm_userfaultfd_ctx; > #ifdef CONFIG_PER_VMA_LOCK > /* Unstable RCU readers are allowed to read this. */ > struct vma_lock vm_lock ____cacheline_aligned_in_smp; > #endif > + /* > + * For areas with an address space and backing store, > + * linkage into the address_space->i_mmap interval tree. > + * > + */ > + struct { > + struct rb_node rb; > + unsigned long rb_subtree_last; > + } shared; > +#ifdef CONFIG_ANON_VMA_NAME > + /* > + * For private and shared anonymous mappings, a pointer to a null > + * terminated string containing the name given to the vma, or NULL if > + * unnamed. Serialized by mmap_lock. Use anon_vma_name to access. > + */ > + struct anon_vma_name *anon_name; > +#endif > + struct vm_userfaultfd_ctx vm_userfaultfd_ctx; > } __randomize_layout; > > #ifdef CONFIG_NUMA