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Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Maarten Lankhorst , Maxime Ripard , Natalie Vock , Tejun Heo , Oscar Salvador , cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@meta.com Subject: Re: [PATCH v6 0/5] mm/page_counter: move stock from mem_cgroup to page_counter Message-ID: References: <20260916210552.891730-1-joshua.hahnjy@gmail.com> <20260917175701.2343946-1-joshua.hahnjy@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@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="6tot43pwavmchhic" Content-Disposition: inline In-Reply-To: <20260917175701.2343946-1-joshua.hahnjy@gmail.com> --6tot43pwavmchhic Content-Type: text/plain; protected-headers=v1; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Subject: Re: [PATCH v6 0/5] mm/page_counter: move stock from mem_cgroup to page_counter MIME-Version: 1.0 Hi. On Thu, Sep 17, 2026 at 10:57:00AM -0700, Joshua Hahn wrote: >=20 > This is true, but this is already the behavior for vanilla memcg. > In this series I'm hoping to preserve all existing semantics without > changing behaviors, so I can fix this problem in a separate issue. >=20 > Specifically, in vanilla try_charge_memcg: >=20 > done_restock: > if (batch > nr_pages) > refill_stock(memcg, batch - nr_pages); >=20 > ... > current->memcg_nr_pages_over_high +=3D batch; >=20 > So I've just preserved the exact semantics that we used to have before. Kudos to you for the conservative approach. >=20 > The problem isn't that big anyways though, it's a transient inflation > in memcg_over_high and will be wiped on the next high handling run, > and there is no effect on accounting or permanent inflations. It reminds me [1] where stockage imprecision could even trigger OOM but it was reportedly only visible in LTP. HTH, Michal [1] https://lore.kernel.org/all/20250530151858.672391-1-mkoutny@suse.com/ --6tot43pwavmchhic Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iJEEABYKADkWIQRCE24Fn/AcRjnLivR+PQLnlNv4CAUCaqzvFhsUgAAAAAAEAA5t YW51MiwyLjUrMS4xMiwyLDIACgkQfj0C55Tb+AiyGQEAxBEcNkVlUsFJunbUaXyj fCr+UQ4r8t6S3GNeKJPgiYYA/3Gky8F7pWf3EmNRaSTu35DLuveVmYfJTnxV3o4s qHYK =tu6R -----END PGP SIGNATURE----- --6tot43pwavmchhic--