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Wed, 25 Feb 2026 04:19:24 -0800 (PST) MIME-Version: 1.0 References: <20260220-swap-table-p4-v1-0-104795d19815@tencent.com> <20260220-swap-table-p4-v1-12-104795d19815@tencent.com> In-Reply-To: <20260220-swap-table-p4-v1-12-104795d19815@tencent.com> From: Barry Song <21cnbao@gmail.com> Date: Wed, 25 Feb 2026 20:19:14 +0800 X-Gm-Features: AaiRm511TxBGRVuIyMzvT0fAaZozlquA48wNCycgFlMQWIgQStFaENf0SwcgBCQ Message-ID: Subject: Re: [PATCH RFC 12/15] mm, swap: merge zeromap into swap table To: kasong@tencent.com Cc: linux-mm@kvack.org, Andrew Morton , David Hildenbrand , Lorenzo Stoakes , Zi Yan , Baolin Wang , Hugh Dickins , Chris Li , Kemeng Shi , Nhat Pham , Baoquan He , Johannes Weiner , Yosry Ahmed , Youngjun Park , Chengming Zhou , Roman Gushchin , Shakeel Butt , Muchun Song , Qi Zheng , linux-kernel@vger.kernel.org, cgroups@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Stat-Signature: us5s8qwyiqnbm67qygj1bd7t9ea51ras X-Rspamd-Server: rspam11 X-Rspam-User: X-Rspamd-Queue-Id: 3C289180002 X-HE-Tag: 1772021965-80962 X-HE-Meta: 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 okEWCY4b UX0uURgKjs3KQgbAqRpRU3wBfMk8W6yG5zpV7w/tGqg6MotvC3tMrroN/P6tnwE4Mu06LTlHmumHuAUxvFneqDzCZwRnnA31I/0fot1sgnRp6gcsbEEnCJpjnaeCaPkYz8co5wt2ZU7dsGYF3RCMaam+W+T1Sp3VcfSguzdhYvkdmbNb8hMvHJ1d68KJ5sJMY5jmBcU1/DkjZoG+6GhUhmr2862k9OiNFnWVkarGrZ624W2j8RYiiHi/0i8BRQvcQWcdSeZRC3YNIFvwmKUhmUv7qncJ+1212IlQ/BvtA6Yspt1cB6/5FU+vtzlVO3ZDSlKB5lMImYLOJTu17jDsH8oEyEpZRM1TchKsCifhcRu70e6Uaq/zYAUD4cjl+4lqf3n1JWV2FYBHLKCatVLItOBF1kbASkxpmKeu1T8nkBwghng7C5uzqceelzJlZc4JaQdmd Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Fri, Feb 20, 2026 at 7:42=E2=80=AFAM Kairui Song via B4 Relay wrote: > > From: Kairui Song > > By reserving one bit for the counting part, we can easily merge the > zeromap into the swap table. Hi Kairui, I know you're saving space by removing the zeromap memory, but do you think a bitmap can sometimes be faster than iterating over multiple data points to set or get bits? Or is the performance difference too small to notice? Thanks Barry