package/kernel/linux/up-next-remove-lru_add_drain.patch

   1 From mboxrd@z Thu Jan  1 00:00:00 1970
   2 Return-Path: <owner-linux-mm@kvack.org>
   3 X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on
   4         aws-us-west-2-korg-lkml-1.web.codeaurora.org
   5 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17])
   6         by smtp.lore.kernel.org (Postfix) with ESMTP id 193ECE77184
   7         for <linux-mm@archiver.kernel.org>; Thu, 19 Dec 2024 20:33:50 +0000 (UTC)
   8 Received: by kanga.kvack.org (Postfix)
   9         id 2F32B6B007B; Thu, 19 Dec 2024 15:33:50 -0500 (EST)
  10 Received: by kanga.kvack.org (Postfix, from userid 40)
  11         id 2A1726B0082; Thu, 19 Dec 2024 15:33:50 -0500 (EST)
  12 X-Delivered-To: int-list-linux-mm@kvack.org
  13 Received: by kanga.kvack.org (Postfix, from userid 63042)
  14         id 1928F6B0083; Thu, 19 Dec 2024 15:33:50 -0500 (EST)
  15 X-Delivered-To: linux-mm@kvack.org
  16 Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17])
  17         by kanga.kvack.org (Postfix) with ESMTP id EE4376B007B
  18         for <linux-mm@kvack.org>; Thu, 19 Dec 2024 15:33:49 -0500 (EST)
  19 Received: from smtpin26.hostedemail.com (a10.router.float.18 [10.200.18.1])
  20         by unirelay06.hostedemail.com (Postfix) with ESMTP id 6B494AE202
  21         for <linux-mm@kvack.org>; Thu, 19 Dec 2024 20:33:49 +0000 (UTC)
  22 X-FDA: 82912858770.26.CB136A0
  23 Received: from shelob.surriel.com (shelob.surriel.com [96.67.55.147])
  24         by imf05.hostedemail.com (Postfix) with ESMTP id F18B610000C
  25         for <linux-mm@kvack.org>; Thu, 19 Dec 2024 20:32:43 +0000 (UTC)
  26 Authentication-Results: imf05.hostedemail.com;
  27         dkim=none;
  28         spf=pass (imf05.hostedemail.com: domain of riel@shelob.surriel.com designates 96.67.55.147 as permitted sender) smtp.mailfrom=riel@shelob.surriel.com;
  29         dmarc=none
  30 ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com;
  31         s=arc-20220608; t=1734640405;
  32         h=from:from:sender:sender:reply-to:subject:subject:date:date:
  33          message-id:message-id:to:to:cc:cc:mime-version:mime-version:
  34          content-type:content-type:
  35          content-transfer-encoding:content-transfer-encoding:in-reply-to:
  36          references; bh=0Ccq0U+3IOI/6eUxIxyV7Tfz5Kok9xBMqUuSAaMouNM=;
  37         b=cUr+VthX13DHsxJrlm8zlEuG7HU8UVXztQEt/GjPX9r/nmgX7BUm9w4QHXRLQWq/OSCULy
  38         e7xHAoQjIBQujLlig5PgkUkMeXVih/xE/QwWAolYRkisAGYRF0jG+UXVax1AcjGlHH7wrG
  39         dtrB9vNwvDZkqxyzz1Fp+iVPqOTQPwI=
  40 ARC-Authentication-Results: i=1;
  41         imf05.hostedemail.com;
  42         dkim=none;
  43         spf=pass (imf05.hostedemail.com: domain of riel@shelob.surriel.com designates 96.67.55.147 as permitted sender) smtp.mailfrom=riel@shelob.surriel.com;
  44         dmarc=none
  45 ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1734640405; a=rsa-sha256;
  46         cv=none;
  47         b=7GCLnUaIzOphp9jZphNrYYSJdhiYACtuFanUiOSgIquPyrB8zpZpFuGzfQZFWDpgcsUA6K
  48         tsaCUxnSOLRzlEuSn1Hl3EG8EyFHJdmRiBx6lIo05oFWiIS83rrI5dpyDI5Vu4cI8rkwVr
  49         I8wxmECw6wPbbecxBYhMQP76Xd9ajro=
  50 Received: from [2601:18c:9101:a8b6:82e7:cf5d:dfd9:50ef] (helo=fangorn)
  51         by shelob.surriel.com with esmtpsa  (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
  52         (Exim 4.97.1)
  53         (envelope-from <riel@shelob.surriel.com>)
  54         id 1tONCY-000000002Ni-0at9;
  55         Thu, 19 Dec 2024 15:32:54 -0500
  56 Date: Thu, 19 Dec 2024 15:32:53 -0500
  57 From: Rik van Riel <riel@surriel.com>
  58 To: Shakeel Butt <shakeel.butt@linux.dev>
  59 Cc: David Hildenbrand <david@redhat.com>, Andrew Morton
  60  <akpm@linux-foundation.org>, Chris Li <chrisl@kernel.org>, Ryan Roberts
  61  <ryan.roberts@arm.com>, "Matthew Wilcox (Oracle)" <willy@infradead.org>,
  62  linux-mm@kvack.org, kernel-team@meta.com, linux-kernel@vger.kernel.org
  63 Subject: [PATCH] mm: remove unnecessary calls to lru_add_drain
  64 Message-ID: <20241219153253.3da9e8aa@fangorn>
  65 X-Mailer: Claws Mail 4.3.0 (GTK 3.24.43; x86_64-redhat-linux-gnu)
  66 MIME-Version: 1.0
  67 Content-Type: text/plain; charset=US-ASCII
  68 Content-Transfer-Encoding: 7bit
  69 X-Rspamd-Server: rspam05
  70 X-Stat-Signature: r799eok86s1fuxscnksmbwond59pifab
  71 X-Rspamd-Queue-Id: F18B610000C
  72 X-Rspam-User:
  73 X-HE-Tag: 1734640363-876383
  74 X-HE-Meta: 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
  75  4VDb1Caj
  76  U/lhyJog/VY12eZsu6A4DNqaQh2ldyOu8ooNRuCYJI2mMdIY5BvHsISv1xdeUG0Vr7eif4wgSy/LeuU1652jP6WnVZ35O7c6s0nqTXlgfk8LSNvvuoJobyTR6muS94MpI7/mkQtvmoqBK71BHJuTgoMbgNKUSt37p1AIziqrgfkKP/LVZbjWorN+TOaK1oOjNuygSQ/b6+Li6I9Gl5mWV3tit+/R3C0ypgH+Dn90PnyFdxoPyFLt5iVGrHBAAdWjmGWBfmS7HCqEqLiy5WU3xSnCf+t+FKzWX89kPrOOtCs2PaI/EH4DMVpgUQM/PGskQP3ck0vmWUtgyYu/Ma98mbi6uH0GN1/98vHfJLgWRNgwUecuWE77aqlsCl0W7MlCEGgkETWY83tV0Q6aboxCtCD930zo36zU+YHei
  77 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4
  78 Sender: owner-linux-mm@kvack.org
  79 Precedence: bulk
  80 X-Loop: owner-majordomo@kvack.org
  81 List-ID: <linux-mm.kvack.org>
  82 List-Subscribe: <mailto:majordomo@kvack.org>
  83 List-Unsubscribe: <mailto:majordomo@kvack.org>
  84
  85 There seem to be several categories of calls to lru_add_drain
  86 and lru_add_drain_all.
  87
  88 The first are code paths that recently allocated, swapped in,
  89 or otherwise processed a batch of pages, and want them all on
  90 the LRU. These drain pages that were recently allocated,
  91 probably on the local CPU.
  92
  93 A second category are code paths that are actively trying to
  94 reclaim, migrate, or offline memory. These often use lru_add_drain_all,
  95 to drain the caches on all CPUs.
  96
  97 However, there also seem to be some other callers where we
  98 aren't really doing either. They are calling lru_add_drain(),
  99 despite operating on pages that may have been allocated
 100 long ago, and quite possibly on different CPUs.
 101
 102 Those calls are not likely to be effective at anything but
 103 creating lock contention on the LRU locks.
 104
 105 Remove the lru_add_drain calls in the latter category.
 106
 107 Signed-off-by: Rik van Riel <riel@surriel.com>
 108 Suggested-by: David Hildenbrand <david@redhat.com>
 109 ---
 110  mm/memory.c     | 1 -
 111  mm/mmap.c       | 2 --
 112  mm/swap_state.c | 1 -
 113  mm/vma.c        | 2 --
 114  4 files changed, 6 deletions(-)
 115
 116 diff --git a/mm/memory.c b/mm/memory.c
 117 index 75c2dfd04f72..95ce298dc254 100644
 118 --- a/mm/memory.c
 119 +++ b/mm/memory.c
 120 @@ -1935,7 +1935,6 @@ void zap_page_range_single(struct vm_area_struct *vma, unsigned long address,
 121         struct mmu_notifier_range range;
 122         struct mmu_gather tlb;
 123
 124 -       lru_add_drain();
 125         mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma->vm_mm,
 126                                 address, end);
 127         hugetlb_zap_begin(vma, &range.start, &range.end);
 128 diff --git a/mm/mmap.c b/mm/mmap.c
 129 index d32b7e701058..ef57488f1020 100644
 130 --- a/mm/mmap.c
 131 +++ b/mm/mmap.c
 132 @@ -1660,7 +1660,6 @@ void exit_mmap(struct mm_struct *mm)
 133                 goto destroy;
 134         }
 135
 136 -       lru_add_drain();
 137         flush_cache_mm(mm);
 138         tlb_gather_mmu_fullmm(&tlb, mm);
 139         /* update_hiwater_rss(mm) here? but nobody should be looking */
 140 @@ -2103,7 +2102,6 @@ int relocate_vma_down(struct vm_area_struct *vma, unsigned long shift)
 141                                        vma, new_start, length, false, true))
 142                 return -ENOMEM;
 143
 144 -       lru_add_drain();
 145         tlb_gather_mmu(&tlb, mm);
 146         next = vma_next(&vmi);
 147         if (new_end > old_start) {
 148 diff --git a/mm/swap_state.c b/mm/swap_state.c
 149 index e0c0321b8ff7..ca42b2be64d9 100644
 150 --- a/mm/swap_state.c
 151 +++ b/mm/swap_state.c
 152 @@ -317,7 +317,6 @@ void free_pages_and_swap_cache(struct encoded_page **pages, int nr)
 153         struct folio_batch folios;
 154         unsigned int refs[PAGEVEC_SIZE];
 155
 156 -       lru_add_drain();
 157         folio_batch_init(&folios);
 158         for (int i = 0; i < nr; i++) {
 159                 struct folio *folio = page_folio(encoded_page_ptr(pages[i]));
 160 diff --git a/mm/vma.c b/mm/vma.c
 161 index 8e31b7e25aeb..d84e5ef6d15b 100644
 162 --- a/mm/vma.c
 163 +++ b/mm/vma.c
 164 @@ -398,7 +398,6 @@ void unmap_region(struct ma_state *mas, struct vm_area_struct *vma,
 165         struct mm_struct *mm = vma->vm_mm;
 166         struct mmu_gather tlb;
 167
 168 -       lru_add_drain();
 169         tlb_gather_mmu(&tlb, mm);
 170         update_hiwater_rss(mm);
 171         unmap_vmas(&tlb, mas, vma, vma->vm_start, vma->vm_end, vma->vm_end,
 172 @@ -1130,7 +1129,6 @@ static inline void vms_clear_ptes(struct vma_munmap_struct *vms,
 173          * were isolated before we downgraded mmap_lock.
 174          */
 175         mas_set(mas_detach, 1);
 176 -       lru_add_drain();
 177         tlb_gather_mmu(&tlb, vms->vma->vm_mm);
 178         update_hiwater_rss(vms->vma->vm_mm);
 179         unmap_vmas(&tlb, mas_detach, vms->vma, vms->start, vms->end,
 180 --
 181 2.47.0
 182
 183
 184