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Szmigiero" , Andrew Morton , Nhat Pham , Chengming Zhou , linux-mm@kvack.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: 9CCD040003 X-Rspam-User: X-Stat-Signature: sc586nrnnmjw15eidu1qw5c9xa7d618d X-Rspamd-Server: rspam01 X-HE-Tag: 1711736599-534666 X-HE-Meta: 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 52i/TbtR vtPWwmcehM9cXwbJZIZg+jmwgX0xs6ep51VoP9E2mapXNnHvIcnMBJV8Hf0sA0lN4ksJDJuJ0K24CoayXLedd+zU2pDPuTFnPEMrJpRAkuBYrLpRZvgNndiPpINDJ4CAJZPDNBurbviI+2HefskWGnsI4dIQVeUnfnCafCy2kq3k8KUPTmZBU6C0B23V7hXRo3+mGAqmaaiTR5XBGTr0ZEB1eJyT6tN4mNIgJ+ckmFCVoAYL1M2PLiv8qcv1/b6Z+IJBHthxIsNI/pBZUZq9mnNXfFJhx7W+mvvLkqPnGkP8TWx3oazAevd8fpFpEHxQNeV/f+Fqe3f6wQ6js3sfS5sKddmoIN0mfQvdGKl6U5nPD76jKtxg7Zh7QFprXz3+zTGNvJyS3/qGOJjbhL2SG6ek778iNQX5D9r9mAJ3Ifhg2TnjPbgUFJjLJzQ== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000001, 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 Fri, Mar 29, 2024 at 10:45=E2=80=AFAM Johannes Weiner wrote: > > On Fri, Mar 29, 2024 at 03:02:10PM +0100, Maciej S. Szmigiero wrote: > > On 29.03.2024 03:14, Yosry Ahmed wrote: > > > On Thu, Mar 28, 2024 at 1:06=E2=80=AFPM Yosry Ahmed wrote: > > >> > > >> On Thu, Mar 28, 2024 at 12:11=E2=80=AFPM Johannes Weiner wrote: > > >>> > > >>> On Mon, Mar 25, 2024 at 11:50:13PM +0000, Yosry Ahmed wrote: > > >>>> There is no logical reason to refuse storing same-filled pages mor= e > > >>>> efficiently and opt for compression. Remove the userspace knob. > > >>>> > > >>>> Signed-off-by: Yosry Ahmed > > >>> > > >>> Acked-by: Johannes Weiner > > >>> > > >>> I also think the non_same_filled_pages_enabled option should go > > >>> away. Both of these tunables are pretty bizarre. > > >> > > >> Happy to remove both in the next version :) > > > > > > I thought non_same_filled_pages_enabled was introduced with the > > > initial support for same-filled pages, but it was introduced > > > separately (and much more recently): > > > https://lore.kernel.org/all/7dbafa963e8bab43608189abbe2067f4b9287831.= 1641247624.git.maciej.szmigiero@oracle.com/ > > > > > > I am CCing Maciej to hear more about the use case for this. > > > > Thanks for CCing me. > > > > I introduced "non_same_filled_pages_enabled" a few years ago to > > enable using zswap in a lightweight mode where it is only used for > > its ability to store same-filled pages effectively. > > But all the pages it rejects go to disk swap instead, which is much > slower than compression... > > > As far as I remember, there were some interactions between full > > zswap and the cgroup memory controller - like, it made it easier > > for an aggressive workload to exceed its cgroup memory.high limits. > > Ok, that makes sense! A container fairness measure, rather than a > performance optimization. > > Fair enough, but that's moot then with cgroup accounting of the > backing memory, f4840ccfca25 ("zswap: memcg accounting"). Right, this should no longer be needed with the zswap charging. Maciej, is this still being used on kernels with f4840ccfca25 (5.19+)? Any objections to removing it now?