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Mon, 19 Jan 2026 13:43:23 -0800 (PST) MIME-Version: 1.0 References: <20260116044841.334821-1-senozhatsky@chromium.org> In-Reply-To: <20260116044841.334821-1-senozhatsky@chromium.org> From: Nhat Pham Date: Mon, 19 Jan 2026 13:43:12 -0800 X-Gm-Features: AZwV_QjkdE-CDaIoPzn36Rrcg5-JIGXzqMTKsE7daaqmbXMcnYgB6SNBKBKc8mA 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-Rspamd-Queue-Id: 1B46780004 X-Stat-Signature: uwy3ddqukakrc6sjkjwi38nmsx689bmu X-Rspam-User: X-Rspamd-Server: rspam05 X-HE-Tag: 1768859004-830632 X-HE-Meta: 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 ivDGerVo 5A09lqnTXYVWvyNtYhhxch1ycygY5I8Kpjor+d7TWqSG2IOtutfkruwa0OEctqi524fitOsnuweYN+sbri02wJbpRUNMrH1lYYGNZ6bTEKkchHxQYQg1H7Fdh+Enp8oF1L7Bz8ZZACDCZHdeecE6kTzZp+6LfDFoRhFFRFRMohTJPjcp3Utj4chrfYqHSug72Zf6Fhq1wYCBuOtjwQ3k+REmSf+t4mbvPgiCGs4fMEd7DolYfAgKHNCbfMpEYmzTnmSW0YBEQTTz1HzE00E2zsNw18HOwafmEZSgTpnQmewTbpxXiNADjy10+HlULwcdLV6sYazsqYC0ZKzZYXYk3FUDWVYgPjslzMOcuKvwWwlzfUkjTBVk0jyvb271SBZRNi13dSdaFr6QLAsl0N9bVYG6O9Anvmjq4gM0twNQSSFlR3dE= 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 8:49=E2=80=AFPM 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. > > Make handles and zspages kmem caches global. Hmm yeah this sounds reasonable to me. No reason to have dedicated kmem_cache per zs_pool (in the case of zswap, I suppose it's one for each compression algorithm, which is usually just one - but still...). Is there any lock contention implications? >