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 66C4DC27C4F for ; Thu, 13 Jun 2024 09:58:51 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id AD08D6B009D; Thu, 13 Jun 2024 05:58:50 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A80416B009E; Thu, 13 Jun 2024 05:58:50 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 91FE76B009F; Thu, 13 Jun 2024 05:58:50 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 6FF286B009D for ; Thu, 13 Jun 2024 05:58:50 -0400 (EDT) Received: from smtpin15.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 18B6DA2399 for ; Thu, 13 Jun 2024 09:58:50 +0000 (UTC) X-FDA: 82225416420.15.1D16B80 Received: from mail-ua1-f44.google.com (mail-ua1-f44.google.com [209.85.222.44]) by imf23.hostedemail.com (Postfix) with ESMTP id 43DE0140010 for ; Thu, 13 Jun 2024 09:58:47 +0000 (UTC) Authentication-Results: imf23.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b="RbUobA/F"; spf=pass (imf23.hostedemail.com: domain of 21cnbao@gmail.com designates 209.85.222.44 as permitted sender) smtp.mailfrom=21cnbao@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1718272725; 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=PISS48tZawjaWikz7z/zrvsV2Sl+fMVlabGyAg/WHjg=; b=2KtdSJNUwcolEtyIc4BVNcGiO+KUgDWras46OKGxPtVBz6h9m5oOgY7fDM/Txn8BuXBH0u +ZKj7EcvfofhhziSznakWMHn097oGtZJ19gFho52mWFy7/ZMQTwzdDchJsSUy0uo91EjwY wMEQt4wpWdGphCBS1QZwfI5KqVuBCEc= ARC-Authentication-Results: i=1; imf23.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b="RbUobA/F"; spf=pass (imf23.hostedemail.com: domain of 21cnbao@gmail.com designates 209.85.222.44 as permitted sender) smtp.mailfrom=21cnbao@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1718272725; a=rsa-sha256; cv=none; b=PldDLVeHnqEvsOMnGJKZX0Yjrue7orKafyr3JUpuRdqwd3pCnsCtDXL6fmSBQMZviAlcRN 9CHDykcbMl/D8/qAQ6FA0Dzw0zUp6wQHKUc8Ua4jG+cQ7jw6hK+iO9sxET9RfemEhEq/45 Yk0phQIFUCVDsONcmZZHW7SNI1vLVMU= Received: by mail-ua1-f44.google.com with SMTP id a1e0cc1a2514c-80b89287c58so139002241.3 for ; Thu, 13 Jun 2024 02:58:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1718272726; x=1718877526; 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=PISS48tZawjaWikz7z/zrvsV2Sl+fMVlabGyAg/WHjg=; b=RbUobA/FXY1mNdv92dUXzlpwBnUJsb9ZR1q2HtYUx+o0Z1xVCgdFiRgO4zf+4vBNrq GPeVZeNt9YsmQLYP1/r//l8Et+KLFPvUkemRnPVnhW7c2kblGZ+80aWJtBDBBz0CrPUW AMy/2rx1bj0OYTEd5wii7pWylYXKFRm0PQrxfvk1ZPKFyvI8qSPl78JV+LknF/ewBMzE 4qD0rrG5EBPQ1a/yf1ZPZwYFOsdEB5Mdw0eoLH62zdsYyC7kS1jdw1nk1zUVrk3zHaAW GE2LC5Q+7n/xHyt7yP0J+BowAUIJz7gYBGSrkZnJCILLIQKH8CwqOWxKsDtnJnTvaESg IyZw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1718272726; x=1718877526; 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=PISS48tZawjaWikz7z/zrvsV2Sl+fMVlabGyAg/WHjg=; b=hPeTqG3z/9srk5rhlfQasdyL0gRyflglfdIkORct80nCiON5A8ulO4ARoAk+ph26zn +GIqO8yK3ZkzALw+RyN0/pciMGGr9UkKjIFpCm940nduZVHnL7JWB/0Gu2j93ccqAumS vAoIAOKLCKWZR/T9V+rg5daBa7wbSjwLLC+Ft721MUw7qiVa0JaTyqY/2rECqC4YUPh3 Bl8QlX1KwZJC/iBE8Nxcsi1Tf3RvkYnCjajBPH0Liz0WY30azmocRbUtnowO5btLCIO5 zBTmN5p8pJXgzbS4/h+aBPQAZOJtjnP4Ods7shjXIpOis5GH/iLG08aSFZU2uBPBhkD4 Ad9A== X-Forwarded-Encrypted: i=1; AJvYcCXDLJ21YmRU0cFbv2K8JG6qbMHpJ739/yTynOX6FQ66wRUPeqC2c5SN7oK0D7Snm+mL+WDKXKOVRSn3cEgx8A4Ha90= X-Gm-Message-State: AOJu0YxKNhh6O/GPVUxH/Q6CRU2Nd072K1brdgwRcL6Yf/UBR4kPUCQd FvoCdktVd6YUJYzUfguk3fTYnIZpbHnZSGp4DOWUT11Db8Kb3jOj1tmuD9NedmPDj7d8O4nEv1g zX+m834eYDgV17n7qRXqwsSob5jQ= X-Google-Smtp-Source: AGHT+IHQ2XzGpscWrWx/gXlH+D2XG780duCe40ms54wbZIL1i333OYL+Z/epIDW7H9Oi9eZCBLs8FGCFWp1W/T0CMc4= X-Received: by 2002:a67:f4d8:0:b0:47c:ac1:6f84 with SMTP id ada2fe7eead31-48d91d92523mr4271384137.2.1718272726252; Thu, 13 Jun 2024 02:58:46 -0700 (PDT) MIME-Version: 1.0 References: <20240613000721.23093-1-21cnbao@gmail.com> <20240613000721.23093-3-21cnbao@gmail.com> <77da1feb-2257-4545-9427-5729250ceb2b@redhat.com> In-Reply-To: <77da1feb-2257-4545-9427-5729250ceb2b@redhat.com> From: Barry Song <21cnbao@gmail.com> Date: Thu, 13 Jun 2024 21:58:35 +1200 Message-ID: Subject: Re: [PATCH RFC 2/3] mm: do_swap_page: use folio_add_new_anon_rmap() if folio_test_anon(folio)==false To: David Hildenbrand Cc: akpm@linux-foundation.org, linux-mm@kvack.org, chrisl@kernel.org, linux-kernel@vger.kernel.org, mhocko@suse.com, ryan.roberts@arm.com, baolin.wang@linux.alibaba.com, yosryahmed@google.com, shy828301@gmail.com, surenb@google.com, v-songbaohua@oppo.com, willy@infradead.org, ying.huang@intel.com, yuzhao@google.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 43DE0140010 X-Stat-Signature: jpx9ycmsso7aius7c6z57gp339hp5675 X-Rspam-User: X-HE-Tag: 1718272727-617087 X-HE-Meta: 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 l76SsBSe fRDWeSq6hCB7055BaOKF1C1z4GscN5FxYhvUaF/90EBDfZ1RqXdx0mY+XvujLd8P69IGS77dlEGuqUWZ3sQkjDX7szc3AP0vg7lhXPck8nR5MQAcSQnDsUL+iYy5znAavMzPkzwaqwH6qmGfPoKJ7nxRIm1QU+A/2nCjzUIMLMcT+Q9LOQiR+IXWRF8j6Fo1KLoxi3oScFxEJ/4M4AKVajs2ZBflSykn+rBmd06wfcdsXOejriOLLZ3P68z9LqTe2FO9paLP0JDFpEMHK0p86VniBTgmv4H8CSfQPNKMZSkTCglwkQ+s8nXPLOh7vSof8hYTrUEkAVwd+SBaW8JIl339oiuv+0tzrPHZR4/Dl8+PdF9RHMKqf0Bi3CNciJSot7MfeEJhhgth1bEdm8kAdvfDCB5evEw9qYwewEe03C8BYXUw= 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 Thu, Jun 13, 2024 at 9:23=E2=80=AFPM David Hildenbrand wrote: > > On 13.06.24 02:07, Barry Song wrote: > > From: Barry Song > > > > For the !folio_test_anon(folio) case, we can now invoke folio_add_new_a= non_rmap() > > with the rmap flags set to either EXCLUSIVE or non-EXCLUSIVE. This acti= on will > > suppress the VM_WARN_ON_FOLIO check within __folio_add_anon_rmap() whil= e initiating > > the process of bringing up mTHP swapin. > > > > static __always_inline void __folio_add_anon_rmap(struct folio *folio= , > > struct page *page, int nr_pages, struct vm_area_struc= t *vma, > > unsigned long address, rmap_t flags, enum rmap_level = level) > > { > > ... > > if (unlikely(!folio_test_anon(folio))) { > > VM_WARN_ON_FOLIO(folio_test_large(folio) && > > level !=3D RMAP_LEVEL_PMD, folio); > > } > > ... > > } > > > > It also enhances the code=E2=80=99s readability. > > > > Suggested-by: David Hildenbrand > > Signed-off-by: Barry Song > > --- > > mm/memory.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/mm/memory.c b/mm/memory.c > > index 2f94921091fb..9c962f62f928 100644 > > --- a/mm/memory.c > > +++ b/mm/memory.c > > @@ -4339,6 +4339,8 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) > > if (unlikely(folio !=3D swapcache && swapcache)) { > > folio_add_new_anon_rmap(folio, vma, address, RMAP_EXCLUSI= VE); > > folio_add_lru_vma(folio, vma); > > + } else if (!folio_test_anon(folio)) { > > + folio_add_new_anon_rmap(folio, vma, address, rmap_flags); > > So, with large folio swapin, we would never end up here if any swp PTE > is !exclusive, because we would make sure to allocate a large folio only > for suitable regions, correct? > > It can certainly happen during swapout + refault with large folios. But > there, we will always have folio_test_anon() still set and wouldn't run > into this code path. > > (it will all be better with per-folio PAE bit, but that will take some > more time until I actually get to implement it properly, handling all > the nasty corner cases) > > Better add a comment regarding why we are sure that the complete thing > is exclusive (e.g., currently only small folios). No, patch 1/3 enables both cases to call folio_add_new_anon_rmap(). Current= ly, small folios could be non-exclusive. I suppose your question is whether we should ensure that all pages within a mTHP have the same exclusivity status, rather than always being exclusive? > > > } else { > > folio_add_anon_rmap_ptes(folio, page, nr_pages, vma, addr= ess, > > rmap_flags); > > -- > Cheers, > > David / dhildenb > Thanks Barry