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Mon, 19 Jan 2026 13:44:45 -0800 (PST) MIME-Version: 1.0 References: <20260116044841.334821-1-senozhatsky@chromium.org> In-Reply-To: From: Nhat Pham Date: Mon, 19 Jan 2026 13:44:34 -0800 X-Gm-Features: AZwV_Qg1CrMrgazcbkOBRSxdLw2cz0PEeFMtHTdtPdmwwmjo1Zkn76XdooFf2cE Message-ID: Subject: Re: [RFC PATCH] zsmalloc: make common caches global To: Sergey Senozhatsky Cc: Andrew Morton , Yosry Ahmed , Minchan Kim , Johannes Weiner , Brian Geffon , linux-kernel@vger.kernel.org, linux-mm@kvack.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Stat-Signature: zmj3rzgg6m8q4cubfb6nbusq6ffermkt X-Rspamd-Queue-Id: 57820180003 X-Rspam-User: X-Rspamd-Server: rspam02 X-HE-Tag: 1768859087-791338 X-HE-Meta: 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 ceQdYSHu Ql9qKOvhyrmVZ04XBTPTbE8O6qkm793iF6QowTlFqdescfdqfQ3VK9a4snAA9PDsT2r4JWrZwB6jZhU2+Y4+FgqmnTCdGt6Wtf1cCvS+6b9YJAyvkrQv9LVwGEtofXvZ6181TK9kqQ+whxNkZ+gX5i07rtk5rdYocG4aDODrmeALlzOClbcYZ0+n6j1eRnCBlPq3ZZvF5b1F0Y2jn9WcOA7V3FlgHMjBCW0g21uTdbjoo9Br5kpTYsagTzjLez3iymdGMKEfGWPi5eYpQxohrF4yBBQ8LdmNjygis5WBcq7p2Fypw0+EqEazv8qM6d8/TmlA8zoRjZIC8ZCcFVDFTSl63TkrCZEYwL04enNBx6yoai9ldKnkqSxH6chyw7G7fomrm9yGwJIk7DnUm1ykK1OXMoFFUkHj79zCJt9FyM2bN4kU= 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, Jan 15, 2026 at 9:53=E2=80=AFPM Sergey Senozhatsky wrote: > > On (26/01/16 13:48), Sergey Senozhatsky wrote: > > Currently, zsmalloc creates kmem_cache of handles and zspages > > for each pool, which may be suboptimal from the memory usage > > point of view (extra internal fragmentation per pool). Systems > > that create multiple zsmalloc pools may benefit from shared > > common zsmalloc caches. > > This is step 1. > > Step 2 is to look into possibility of sharing zsmalloc pools. > E.g. if there are N zram devices in the system, do we really need > N zsmalloc pools? Can we just share a single pool between them? Ditto for zswap (although here, we almost always only have a single zswap p= ool).