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 3F3AEE95A8E for ; Sun, 8 Oct 2023 21:48:02 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 921DF6B018D; Sun, 8 Oct 2023 17:48:01 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8AA316B018E; Sun, 8 Oct 2023 17:48:01 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 74B336B018F; Sun, 8 Oct 2023 17:48:01 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 60AF06B018D for ; Sun, 8 Oct 2023 17:48:01 -0400 (EDT) Received: from smtpin15.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 235761A0206 for ; Sun, 8 Oct 2023 21:48:01 +0000 (UTC) X-FDA: 81323632362.15.811E7BE Received: from mail-yw1-f173.google.com (mail-yw1-f173.google.com [209.85.128.173]) by imf02.hostedemail.com (Postfix) with ESMTP id 6052A80017 for ; Sun, 8 Oct 2023 21:47:59 +0000 (UTC) Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=google.com header.s=20230601 header.b=YCxxW6Y1; spf=pass (imf02.hostedemail.com: domain of surenb@google.com designates 209.85.128.173 as permitted sender) smtp.mailfrom=surenb@google.com; dmarc=pass (policy=reject) header.from=google.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1696801679; 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=saCmuxHJpGa9XbhcsyT//y4HdOnn/QiFgJdVJR7b844=; b=URxZnZ1d5Y+L2Q4LGpSzvOy6P6HFBA5p6nu/KThKe2JPoGNCamT7BqWKXml6sl/tUmw2dg Jb5C7/QEAwXH91CClHi7UAOyYWGWbnK/HlWIGVoWzceIsPwno709AksUZGOhW67ePyYXzx vk1EThv5sw32zA2d1DUUJ9CoHouJqk0= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1696801679; a=rsa-sha256; cv=none; b=3lC5HCch9cLkv/LE5ETH/UleCLFvW5JDEbS19bYJ0gz25oKEtKUVw6m4uFqCvmkoHZX64k hlcSojyra0ZaIC61aZGfNKw3yqSafm71h1oQk6Q42jImwzXYKiBZG9eVFXmnN5sCrPpDqx oxZkstr0ZoZR/4b/epDn1leH0hXzLBY= ARC-Authentication-Results: i=1; imf02.hostedemail.com; dkim=pass header.d=google.com header.s=20230601 header.b=YCxxW6Y1; spf=pass (imf02.hostedemail.com: domain of surenb@google.com designates 209.85.128.173 as permitted sender) smtp.mailfrom=surenb@google.com; dmarc=pass (policy=reject) header.from=google.com Received: by mail-yw1-f173.google.com with SMTP id 00721157ae682-59f6e6b206fso49148337b3.3 for ; Sun, 08 Oct 2023 14:47:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1696801678; x=1697406478; 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=saCmuxHJpGa9XbhcsyT//y4HdOnn/QiFgJdVJR7b844=; b=YCxxW6Y1SUeNGM5qpSM0cVW+9to0V7khdzPG/Ogt7+RTVROBt+1Jjl4D/WyDOTS/Hz oFx6XQAj75MkoNxWO4IQ9bDtuIXAPSvK6KizSLjQnvHSve3StfgULlg1wCeIOq5Jvto2 Wd2GMucDnu7u1Phh0Jw2qhXNg8liFfVRov96eR8nd5BJJfp0C2vchI2zpqHRKjQtsqwr 9y6+F1ukpiBfKzB/9f8KTdGOKNHi+sOni6vk9kqmw3wdg/HGs69Hy3wQuyB4RxQukdQi tnA8t6wuVj6khVPmOQauhbXGBesWk2vkcQnNROO9RfTjIsOF0WBKzbKddOnr4xH9RvRm yOvg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1696801678; x=1697406478; 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=saCmuxHJpGa9XbhcsyT//y4HdOnn/QiFgJdVJR7b844=; b=ClDg9Ese34kOT+qKU9tsOMYtx/P3BJtVYZK0+DZMi5/L3IIbwM3H4Z0HL3yxgUVqdI rfwKmerjlS7dB9wFEOsXyG3Y23rdqscvh2MvaybbSej2BAa7tpGiTBqDiYfRgnqHbEOW KgrOcw52xEe9dXaNxnCqRTbGjpEO4iIX+BZz+pIkzHMgDJjpeo8X95LElBwVXT7Va+E/ /w04ifyqwiuhwX4xyPnNLYcaOnzLe6xBm+WQZLM6FN2yntNwo1FdvNAyerwBMlomav5h yPQXCtEANTUsWQ4ef+/MLN68BGiFAetLZNGbbvD6zcebESVMwsuJI22bjTL/fqig4JZA Rbzg== X-Gm-Message-State: AOJu0YzAxaaSVTchxm2Td7O53q04RwwY9g/eqGBl2wzcpLfSEtqCMdUO duU6pi/ODeDLU/URWZvTS/CDa2j38BdA3mESclXHYw== X-Google-Smtp-Source: AGHT+IHCmsylWFSXK1himC34TGPPO3ZO3kdeYrvvek7+abQ0//6XawsvWUdea3Cumd8pgJAj+YmXyrFze6xEK3CcHYI= X-Received: by 2002:a25:23d3:0:b0:d81:c10d:7e1a with SMTP id j202-20020a2523d3000000b00d81c10d7e1amr13029425ybj.58.1696801678186; Sun, 08 Oct 2023 14:47:58 -0700 (PDT) MIME-Version: 1.0 References: <20231006195318.4087158-1-willy@infradead.org> <20231006195318.4087158-2-willy@infradead.org> In-Reply-To: <20231006195318.4087158-2-willy@infradead.org> From: Suren Baghdasaryan Date: Sun, 8 Oct 2023 14:47:45 -0700 Message-ID: Subject: Re: [PATCH v2 1/6] mm: Make lock_folio_maybe_drop_mmap() VMA lock aware To: "Matthew Wilcox (Oracle)" Cc: Andrew Morton , linux-mm@kvack.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: 6052A80017 X-Rspam-User: X-Rspamd-Server: rspam11 X-Stat-Signature: zn7usrse89epdcnqnq4of8jxzo15mnc6 X-HE-Tag: 1696801679-189524 X-HE-Meta: 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 yJX3P4FD 6QuZf7Uf5PbqcpzT5aRVs4WP08HzNSkrvq7NeIiXw646fVes0NMSh4oPKipUky28/9Ify1PoyDbFATXFbInk3dcLs48+TtPGTxJeksl3x+7uwYrtDuUM4Ts292kfIbTN09ApBhwtu/uaQbJNpHHJOTafX+1d5Bk3VnGZ3uN1kuP+bq/sI9xzjfqLZ0bfrtZJ1rfQUUwfRDFy2ztgodobKLHNUOcO8r7+54KMQ3EP5/NHmSEhO6EjdPyaQcg3pSOtHL9ptWZPu3M8ZESKzYVLJ8TKvXrGmNr9x/nbVdRyB2oFaRPHWvDxyajbkWxhcmct00Uw35i0U4+IRQMdkRKaKZTli5Y2n8tcnkmFZ X-Bogosity: Ham, tests=bogofilter, spamicity=0.326683, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, Oct 6, 2023 at 12:53=E2=80=AFPM Matthew Wilcox (Oracle) wrote: > > Drop the VMA lock instead of the mmap_lock if that's the one which > is held. > > Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Suren Baghdasaryan > --- > mm/filemap.c | 13 +++++++------ > 1 file changed, 7 insertions(+), 6 deletions(-) > > diff --git a/mm/filemap.c b/mm/filemap.c > index 9481ffaf24e6..a598872d62cc 100644 > --- a/mm/filemap.c > +++ b/mm/filemap.c > @@ -3104,7 +3104,7 @@ static int lock_folio_maybe_drop_mmap(struct vm_fau= lt *vmf, struct folio *folio, > > /* > * NOTE! This will make us return with VM_FAULT_RETRY, but with > - * the mmap_lock still held. That's how FAULT_FLAG_RETRY_NOWAIT > + * the fault lock still held. That's how FAULT_FLAG_RETRY_NOWAIT > * is supposed to work. We have way too many special cases.. > */ > if (vmf->flags & FAULT_FLAG_RETRY_NOWAIT) > @@ -3114,13 +3114,14 @@ static int lock_folio_maybe_drop_mmap(struct vm_f= ault *vmf, struct folio *folio, > if (vmf->flags & FAULT_FLAG_KILLABLE) { > if (__folio_lock_killable(folio)) { > /* > - * We didn't have the right flags to drop the mma= p_lock, > - * but all fault_handlers only check for fatal si= gnals > - * if we return VM_FAULT_RETRY, so we need to dro= p the > - * mmap_lock here and return 0 if we don't have a= fpin. > + * We didn't have the right flags to drop the > + * fault lock, but all fault_handlers only check > + * for fatal signals if we return VM_FAULT_RETRY, > + * so we need to drop the fault lock here and > + * return 0 if we don't have a fpin. > */ > if (*fpin =3D=3D NULL) > - mmap_read_unlock(vmf->vma->vm_mm); > + release_fault_lock(vmf); > return 0; > } > } else > -- > 2.40.1 >