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Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.151.185] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To canpemm500002.china.huawei.com (7.192.104.244) X-CFilter-Loop: Reflected X-Rspamd-Queue-Id: BA650140025 X-Rspam-User: X-Rspamd-Server: rspam05 X-Stat-Signature: ompyafowiy5r863utxph6ay1ajuy43am X-HE-Tag: 1691475050-580520 X-HE-Meta: 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 hKFoiA6i iThqMZzq5gUFIFJliMDmXO1FM3O3ql4FZvGZfZeWZHdiFgES7jLX044pCgHYVoZnRAsQsSKCiVoy7nRyrT1M8BpGYrv+zdO08Msxn4we1ui4nTPCO3qzgcQmsrll7MTjc5b9PCWWY4bghwg6y8Xf9FWy1flUXM3elUxGRAZfDeMzBg2+cdxZT8nZfnQ== 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: On 2023/8/8 11:26, Matthew Wilcox wrote: > On Tue, Aug 08, 2023 at 04:16:57AM +0100, Matthew Wilcox wrote: >> On Tue, Aug 08, 2023 at 11:08:36AM +0800, Miaohe Lin wrote: >>> On 2023/8/8 10:31, Matthew Wilcox wrote: >>>> On Tue, Aug 08, 2023 at 09:58:31AM +0800, Miaohe Lin wrote: >>>>> kswapd_stop() and kcompactd_stop() are only called when MEMORY_HOTREMOVE >>>>> is enabled. So wrap them under CONFIG_MEMORY_HOTREMOVE and further remove >>>>> __meminit annotation. No functional change intended. >>>> >>>> I don't understand why this is an improvement. If CONFIG_MEMORY_HOTREMOVE >>>> is disabled, the linker drops this section (... right?) If it's enabled, >>> >>> When CONFIG_MEMORY_HOTREMOVE is disabled, without this patch: >>> >>> size mm/compaction.o >>> text data bss dec hex filename >>> 103164 30873 0 134037 20b95 mm/compaction.o >>> >>> size mm/vmscan.o >>> text data bss dec hex filename >>> 158775 49612 64 208451 32e43 mm/vmscan.o >>> >>> while with this patch: >>> >>> size mm/compaction.o >>> text data bss dec hex filename >>> 102915 30865 0 133780 20a94 mm/compaction.o >>> >>> size mm/vmscan.o >>> text data bss dec hex filename >>> 158534 49604 64 208202 32d4a mm/vmscan.o >>> >>> We can reduce each .o by ~250 bytes. >> >> But this is before the linker step! That will be where the meminit >> sections get dropped. Assuming they are; I haven't verified. You need >> to compare before/after of the vmlinux, not the individual .o files. When CONFIG_MEMORY_HOTREMOVE is disabled, without patch: size vmlinux text data bss dec hex filename 70648396 21668938 17985540 110302874 693169a vmlinux while with patch: size vmlinux text data bss dec hex filename 70648128 21668938 17985540 110302606 693158e vmlinux vmlinux is still reduced by 268 bytes. > > Ah, found it: > > #if defined(CONFIG_MEMORY_HOTPLUG) > #define MEM_KEEP(sec) *(.mem##sec) > #define MEM_DISCARD(sec) > #else > #define MEM_KEEP(sec) > #define MEM_DISCARD(sec) *(.mem##sec) > #endif > > in include/asm-generic/vmlinux.lds.h When CONFIG_MEMORY_HOTREMOVE is disabled, without this patch, kswapd_stop() and kcompactd_stop() are dropped after system init. But no insist in this patch. Thanks for your comment.