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charset="utf-8" Content-Transfer-Encoding: quoted-printable X-Stat-Signature: ufxpcn3g5ywqea41na39pyegw66ujcbc X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: A028E8000B X-Rspam-User: X-HE-Tag: 1707846329-684306 X-HE-Meta: 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 Q0Nb50SO 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.024237, 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 Tue, Feb 13, 2024 at 10:31:16PM +0800, Chengming Zhou wrote: > On 2024/2/13 06:42, Yosry Ahmed wrote: > > On Sun, Feb 11, 2024 at 5:58=E2=80=AFAM Chengming Zhou > > wrote: > >> > >> All zswap entries will take a reference of zswap_pool when > >> zswap_store(), and drop it when free. Change it to use the > >> percpu_ref is better for scalability performance. > >> > >> Testing kernel build in tmpfs with memory.max=3D2GB > >> (zswap shrinker and writeback enabled with one 50GB swapfile). > >> > >> mm-unstable zswap-global-lru > >> real 63.20 63.12 > >> user 1061.75 1062.95 > >> sys 268.74 264.44 > >=20 > > Are these numbers from a single run or the average of multiple runs? >=20 > The average of 5 runs. And I just checked/compared each run result, > the improvement is stable. So yes, it should be a real performance gain. >=20 > > It just seems that the improvement is small, and percpu refcnt is > > slightly less intuitive (and uses a bit more memory), so let's make > > sure there is a real performance gain first. >=20 > Right, percpu_ref use a bit more memory which should be ok for our use ca= se, > since we almost have only one zswap_pool to be using. The performance gai= n is > for zswap_store/load hotpath. >=20 > >=20 > > It would also be useful to mention how many threads/CPUs are being used= here. >=20 > My bad, the testing uses 32 threads on a 128 CPUs x86-64 machine. Thanks for the clarification. Please include such details in the commit message.