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 EABD3C433EF for ; Tue, 7 Jun 2022 19:56:46 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 76A766B0085; Tue, 7 Jun 2022 15:56:46 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 71A408D0005; Tue, 7 Jun 2022 15:56:46 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5E2238D0003; Tue, 7 Jun 2022 15:56:46 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 4E24E6B0085 for ; Tue, 7 Jun 2022 15:56:46 -0400 (EDT) Received: from smtpin06.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 1E62921365 for ; Tue, 7 Jun 2022 19:56:46 +0000 (UTC) X-FDA: 79552497612.06.AF9BA5B Received: from mail-lj1-f180.google.com (mail-lj1-f180.google.com [209.85.208.180]) by imf05.hostedemail.com (Postfix) with ESMTP id 5502C10000E for ; Tue, 7 Jun 2022 19:56:44 +0000 (UTC) Received: by mail-lj1-f180.google.com with SMTP id y29so20415601ljd.7 for ; Tue, 07 Jun 2022 12:56:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=ytc01F7z0luLtnnQIAie9i5n4cPFBRqIonpCWXQ9eFQ=; b=AF3nOfLPwJCZqfMLyahEJXj5czEXkl86v/Lg80nyIrpRv5VS8fv6B3w79xvb3vExMD la8+A1pvnO8VD/lTj8a7JRS51k8E1UvKAY8ypMYEulvdFdqIUdkGFgzih3zzWOFVqclO AZGFgAC7J3C3VykjHOIHdI5UEvWUGw3fqJstlEswvfKPPF94IsGKi7N+zC5WFwOn0iYJ 7uRsGWAKOwINaFoForT5gJB5GmCnRZ1Y9OOY9WOz3BwXl2TaeLRqcd7JKjKGKmeXzVvu 6abkiZ8U9B8aubCPtDx7KfNgf/TX4DKwVOc7L/bp2W+xPTMwMfS40CuUS8UfgG6vKdCN Z+Zg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=ytc01F7z0luLtnnQIAie9i5n4cPFBRqIonpCWXQ9eFQ=; b=CZiOfpYBwIVy2d2Y3rxTtF0fuO6kVwy2Lp2vIZBHQmEWpsQWdc1WVZSHeSC2M7APU1 v3mnfi3CLBFFd1j4x+DLfMuZ4aPOpCcclReAnDj2yKM3xgcf8AEV2PnYkmbnzuZEMSqs iTSMiPHQ1DyqzEMRlLlSH6xz2gSYGLonwDZ4NCGMM01WGZfvm5g4TSOeJd3cyBmdm71U byHB7NMeJ7XR5bBBz8HjwYwwlLYXFtJZ53Pd4kZsIHI4TgshtYih+GbOPH9/EX+nXd8Z yRr8qAYeeGLcH4K+637sXhN0eV+guGjVLTsfydYk//sTWXY7yzr2Te8uKO5HP7DDrxlz dP+w== X-Gm-Message-State: AOAM533RF2PJZfoyVfyafwRfod/l5Eu46lAQe+Kw3+E3T6GlrC0zdWoC QvZOZAJm/OkwVuKRv3ZnFeC8Saiz+F7IKIq1ICw0uA== X-Google-Smtp-Source: ABdhPJy6SILtIRYjKAeOY1BU6CBdWWl0CVA8Hwnqdudv3LzgPy7y24PM1KSJ5MpndToe2MOtUxNKxJb+OtGtTgg27uQ= X-Received: by 2002:a2e:9bc6:0:b0:255:6a55:27f9 with SMTP id w6-20020a2e9bc6000000b002556a5527f9mr19532540ljj.96.1654631803640; Tue, 07 Jun 2022 12:56:43 -0700 (PDT) MIME-Version: 1.0 References: <20220604004004.954674-1-zokeefe@google.com> <20220604004004.954674-6-zokeefe@google.com> In-Reply-To: From: "Zach O'Keefe" Date: Tue, 7 Jun 2022 12:56:07 -0700 Message-ID: Subject: Re: [PATCH v6 05/15] mm/khugepaged: make allocation semantics context-specific To: Yang Shi Cc: Alex Shi , David Hildenbrand , David Rientjes , Matthew Wilcox , Michal Hocko , Pasha Tatashin , Peter Xu , Rongwei Wang , SeongJae Park , Song Liu , Vlastimil Babka , Zi Yan , Linux MM , Andrea Arcangeli , Andrew Morton , Arnd Bergmann , Axel Rasmussen , Chris Kennelly , Chris Zankel , Helge Deller , Hugh Dickins , Ivan Kokshaysky , "James E.J. Bottomley" , Jens Axboe , "Kirill A. Shutemov" , Matt Turner , Max Filippov , Miaohe Lin , Minchan Kim , Patrick Xia , Pavel Begunkov , Thomas Bogendoerfer Content-Type: text/plain; charset="UTF-8" Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=AF3nOfLP; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf05.hostedemail.com: domain of zokeefe@google.com designates 209.85.208.180 as permitted sender) smtp.mailfrom=zokeefe@google.com X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 5502C10000E X-Rspam-User: X-Stat-Signature: euer9of5smksc6osrgora4r7qphz5i3m X-HE-Tag: 1654631804-792212 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: On Mon, Jun 6, 2022 at 1:59 PM Yang Shi wrote: > > On Fri, Jun 3, 2022 at 5:40 PM Zach O'Keefe wrote: > > > > Add a gfp_t flags member to struct collapse_control that allows contexts > > to specify their own allocation semantics. This decouples the > > allocation semantics from > > /sys/kernel/mm/transparent_hugepage/khugepaged/defrag. > > > > khugepaged updates this member for every hugepage processed, since the > > sysfs setting might change at any time. > > > > Signed-off-by: Zach O'Keefe > > --- > > mm/khugepaged.c | 21 +++++++++++++-------- > > 1 file changed, 13 insertions(+), 8 deletions(-) > > > > diff --git a/mm/khugepaged.c b/mm/khugepaged.c > > index 38488d114073..ba722347bebd 100644 > > --- a/mm/khugepaged.c > > +++ b/mm/khugepaged.c > > @@ -92,6 +92,9 @@ struct collapse_control { > > > > /* Last target selected in khugepaged_find_target_node() */ > > int last_target_node; > > + > > + /* gfp used for allocation and memcg charging */ > > + gfp_t gfp; > > }; > > > > /** > > @@ -994,15 +997,14 @@ static bool __collapse_huge_page_swapin(struct mm_struct *mm, > > return true; > > } > > > > -static int alloc_charge_hpage(struct page **hpage, struct mm_struct *mm, > > +static int alloc_charge_hpage(struct mm_struct *mm, struct page **hpage, > > Why did you have to reverse the order of mm and hpage? It seems > pointless and you could save a couple of changed lines. At some point many versions ago I must have thought it was cleaner to be consistent with struct *mm as 1st arg, but agree with unnecessary change and have removed. > > struct collapse_control *cc) > > { > > - gfp_t gfp = alloc_hugepage_khugepaged_gfpmask() | __GFP_THISNODE; > > int node = khugepaged_find_target_node(cc); > > > > - if (!khugepaged_alloc_page(hpage, gfp, node)) > > + if (!khugepaged_alloc_page(hpage, cc->gfp, node)) > > return SCAN_ALLOC_HUGE_PAGE_FAIL; > > - if (unlikely(mem_cgroup_charge(page_folio(*hpage), mm, gfp))) > > + if (unlikely(mem_cgroup_charge(page_folio(*hpage), mm, cc->gfp))) > > return SCAN_CGROUP_CHARGE_FAIL; > > count_memcg_page_event(*hpage, THP_COLLAPSE_ALLOC); > > return SCAN_SUCCEED; > > @@ -1032,7 +1034,7 @@ static void collapse_huge_page(struct mm_struct *mm, unsigned long address, > > */ > > mmap_read_unlock(mm); > > > > - result = alloc_charge_hpage(hpage, mm, cc); > > + result = alloc_charge_hpage(mm, hpage, cc); > > if (result != SCAN_SUCCEED) > > goto out_nolock; > > > > @@ -1613,7 +1615,7 @@ static void collapse_file(struct mm_struct *mm, struct file *file, > > VM_BUG_ON(!IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) && !is_shmem); > > VM_BUG_ON(start & (HPAGE_PMD_NR - 1)); > > > > - result = alloc_charge_hpage(hpage, mm, cc); > > + result = alloc_charge_hpage(mm, hpage, cc); > > if (result != SCAN_SUCCEED) > > goto out; > > > > @@ -2037,8 +2039,7 @@ static void khugepaged_scan_file(struct mm_struct *mm, struct file *file, > > } > > #else > > static void khugepaged_scan_file(struct mm_struct *mm, struct file *file, > > - pgoff_t start, struct page **hpage, > > - struct collapse_control *cc) > > + pgoff_t start, struct collapse_control *cc) > > Why was the !CONFIG_SHMEM version definition changed, but CONFIG_SHMEM > version was not? Definitely an error - sorry about that. Surprised I didn't get caught by this earlier - must be because the signatures are eventually made equal when struct **hpage is dropped. Have fixed it. > > { > > BUILD_BUG(); > > } > > @@ -2121,6 +2122,9 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages, > > if (unlikely(khugepaged_test_exit(mm))) > > goto breakouterloop; > > > > + /* reset gfp flags since sysfs settings might change */ > > + cc->gfp = alloc_hugepage_khugepaged_gfpmask() | > > + __GFP_THISNODE; > > VM_BUG_ON(khugepaged_scan.address < hstart || > > khugepaged_scan.address + HPAGE_PMD_SIZE > > > hend); > > @@ -2255,6 +2259,7 @@ static int khugepaged(void *none) > > struct mm_slot *mm_slot; > > struct collapse_control cc = { > > .last_target_node = NUMA_NO_NODE, > > + /* .gfp set later */ > > Seems pointless to me. Ack. Removed. > > }; > > > > set_freezable(); > > -- > > 2.36.1.255.ge46751e96f-goog > >