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Howlett" , Andrew Morton , Chengming Zhou , Johannes Weiner , Jonathan Corbet , Lorenzo Stoakes , Michal Hocko , Mike Rapoport , Suren Baghdasaryan , Vlastimil Babka , Yosry Ahmed , kernel-team@meta.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Takero Funaki Subject: Re: [RFC PATCH v2] mm/zswap: store X-Mailer: git-send-email 2.39.5 In-Reply-To: <2fa2f288-bb82-4a9b-8dec-3a4c768fb970@redhat.com> References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: A0F04A0009 X-Stat-Signature: 3qze1bqigqax31i5kkhcr8idnkq5mdpu X-Rspam-User: X-Rspamd-Server: rspam07 X-HE-Tag: 1754585441-40779 X-HE-Meta: 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 DlGqV2PT l8ocZSkUfY+bMgMXNKNMpu8b81XrqekcUYaIf6SvxauQmE2l0r0QVh3myzzBlZmc2I0oRTyuLj8S4lhK+xJw18qs29RpLo6Qgkjo3LD+Vb/lHZe9RnI+F/ncoWIJ4OxB/sxShl5alCju7oMvQl/jBDl6pLnK7DxPg00sjnTM7OAnXfa13/CpNxJbJ+8dgnqpIci2sWIY+3VIE/a4W6mS+3HQrjMBCsrRSkHioF65G4XPGIB2mP1x5D79v+YZhP74pCOwufyEeFpzHfkdkudMkanpl0Q== 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, 7 Aug 2025 07:55:27 +0200 David Hildenbrand wrote: > On 07.08.25 01:48, Shakeel Butt wrote: > > On Wed, Aug 06, 2025 at 10:14:39PM +0200, David Hildenbrand wrote: > >> > >> But yeah, whether these "as is" pages are movable or not is a good question > >> as well -- in particular when zsmalloc supports page migration and the "as > >> is" pages would not. > > > > By "as is" page, do you mean the page which the reclaim code is trying > > to reclaim or the page within zsmalloc on which the content of original > > pages are copied as is? > > I mean whatever the "dst" is here. > > + if (zswap_save_as_is(comp_ret, dlen, page)) { > + comp_ret = 0; > + dlen = PAGE_SIZE; > + memcpy_from_page(dst, page, 0, dlen); > > IIUC SJ correctly, in case of zsmalloc "dst" is just the same page that > would have stored encrypted data. You correctly understood me. > > If that is the case, nothing should change, really. > > Thanks for clarifying, all! Thank you for asking this important question, too, David! :) Thanks, SJ [...]