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[2001:b011:20e0:1b32:d148:19d6:82fa:6094]) by smtp.gmail.com with ESMTPSA id s75-20020a632c4e000000b0042af14719f4sm1900407pgs.51.2022.09.27.12.07.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 27 Sep 2022 12:07:21 -0700 (PDT) Date: Wed, 28 Sep 2022 03:07:13 +0800 From: Chih-En Lin To: Nadav Amit Cc: Andrew Morton , Qi Zheng , David Hildenbrand , Matthew Wilcox , Christophe Leroy , LKML , Linux MM , Luis Chamberlain , Kees Cook , Iurii Zaikin , Vlastimil Babka , William Kucharski , "Kirill A . Shutemov" , Peter Xu , Suren Baghdasaryan , Arnd Bergmann , Tong Tiangen , Pasha Tatashin , Li kunyu , Anshuman Khandual , Minchan Kim , Yang Shi , Song Liu , Miaohe Lin , Thomas Gleixner , Sebastian Andrzej Siewior , Andy Lutomirski , Fenghua Yu , Dinglan Peng , Pedro Fonseca , Jim Huang , Huichun Feng Subject: Re: [RFC PATCH v2 5/9] mm, pgtable: Add a refcount to PTE table Message-ID: References: <20220927162957.270460-1-shiyn.lin@gmail.com> <20220927162957.270460-6-shiyn.lin@gmail.com> <8C7248F0-55E4-4813-9167-C8CD2D02F1D0@vmware.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8C7248F0-55E4-4813-9167-C8CD2D02F1D0@vmware.com> ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1664305642; a=rsa-sha256; cv=none; b=eNbLa9dKGi+lJzdspn1yfqDqwryH6qTQ46lzqXevvUpor/EbS3dlAFHOJr/dDcbEALyp2U 9YD3V2w3oMraaNqiNusdx+Iu83gzLPMaa3tUhL/LEE+4OBlrV5D0fYa89/SJh8zFTTRc2Y GKyvQcXSqWNsTvnnVNTZCiLEKhDasS4= ARC-Authentication-Results: i=1; imf18.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=XKxxvLcI; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf18.hostedemail.com: domain of shiyn.lin@gmail.com designates 209.85.215.173 as permitted sender) smtp.mailfrom=shiyn.lin@gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1664305642; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=TganKE5ujEzwcNzLIUtCyIVdPLaa9W7UwC/PPJN5TMg=; b=gAURQmt8NqAq8DMqWDblE+zO3nwIy6CA0Ybnk2UoNfa0sWEiI0BfNECttZqgeIzyu88J1Q KHsnpa37R46qL2KTE6fO0OgBaSu5dxtV+ecjsppqqV44tnXCWrV0Vi789p9SsaNPxm5sVa gTxEL5B3550RY5c7nZkLOQvnn3H4tuI= X-Stat-Signature: 6jtoezajhywa3oakdk43fajxebjyywfm X-Rspamd-Queue-Id: B81421C000B X-Rspam-User: Authentication-Results: imf18.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=XKxxvLcI; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf18.hostedemail.com: domain of shiyn.lin@gmail.com designates 209.85.215.173 as permitted sender) smtp.mailfrom=shiyn.lin@gmail.com X-Rspamd-Server: rspam11 X-HE-Tag: 1664305642-30031 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 Tue, Sep 27, 2022 at 05:59:16PM +0000, Nadav Amit wrote: > Is there some assumption that pmd_get_pte() would not be called between the > page_ref_add_unless() and cow_pte_fallback()? > > Hard to know without comments or context. Yes. It is one of the corner case that I need to handle it. Thanks, Chih-En Lin