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[195.250.132.146]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-47aa039af67sm51255578f8f.17.2026.07.08.12.00.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 08 Jul 2026 12:00:55 -0700 (PDT) Date: Wed, 8 Jul 2026 21:00:54 +0200 From: Michal =?utf-8?Q?Koutn=C3=BD?= To: Yosry Ahmed Cc: Nhat Pham , Zenghui Yu , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, hannes@cmpxchg.org, chengming.zhou@linux.dev, tj@kernel.org, Shuah Khan , mhocko@kernel.org, Roman Gushchin , Shakeel Butt , Muchun Song , Andrew Morton Subject: Re: cgroup/test_zswap failed with "zswpout does not increase after test program" Message-ID: References: Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="65f7eg5vudklrash" Content-Disposition: inline In-Reply-To: --65f7eg5vudklrash Content-Type: text/plain; protected-headers=v1; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Subject: Re: cgroup/test_zswap failed with "zswpout does not increase after test program" MIME-Version: 1.0 On Tue, Jul 07, 2026 at 02:49:56PM -0700, Yosry Ahmed wr= ote: > I would honestly rather use more memory. I think there might be cases > where the flusher is delayed. The flush being slightly delayed is not > technically a bug that we want to see a failure for, but if a large > stats change is not visible that's a user-noticeable behavior that we > want a failure for. >=20 > WDYT? There's already the (recent) page size-based scaling, so the idea with nr_cpus scaling could make the selftest useful on wider range of setups (even page size can be considered as a slight implementation detail leak, thus the justification of nr_cpus dependency). Also, I still think that internally the threshold should be changed to the "harmonic" formula [1] but the selftest can go with the linear dependency for more pronounced effects. Thanks, Michal [1] https://lore.kernel.org/lkml/n6mhkjsxsami3qmczkdh57eep4lmcgbtyl7ox3ajzv= eke44yf6@m4bjevvsr47k/ --65f7eg5vudklrash Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iJEEABYKADkWIQRCE24Fn/AcRjnLivR+PQLnlNv4CAUCak6eYRsUgAAAAAAEAA5t YW51MiwyLjUrMS4xMiwyLDIACgkQfj0C55Tb+AjWUgD+NXLAQPqFouL0lAEWSdLH Q1TGxjtThGe45suKK7NoiLIBAM7klcnhnOTcn3O4JeLz/eHwfK1JWXaF9nVzAX65 8KEK =2aDV -----END PGP SIGNATURE----- --65f7eg5vudklrash--