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charset=UTF-8 Content-Transfer-Encoding: 7bit X-Stat-Signature: prt7keb3bdw64rs3byssetnshx9wexi9 X-Rspamd-Queue-Id: 1B7D1100027 X-Rspamd-Server: rspam10 X-Rspam-User: X-HE-Tag: 1714989656-307355 X-HE-Meta: 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 1mCPk4Ob RmHOxp/nnRbQ473DzMowcpynvFGxckkZiLRBB3MMFyjp02/SLdkh3qfARBxdm0mFQG/MURAGQFKs0vkmHiKrln0vKhYufmRdGT9117fq+X94nFzdfa32/Zhc9VI1PVn7siSnMkCHwGgmeGgVm1E2ddgE29C0pWuh4anTeJYw9FeIJ3+MDKkgYZozLtb6NldSyb9PJFNyjZhX0w2y24jLGM7C19ZbQCKexkOnfk9GQ4ClYiKNct2MQXKY8LVBf9Kus/WlKewgncUifSVSxejj3tQHOysNjmAjWexBy 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 5/6/24 06:51, Wei Yang wrote: > When CONFIG_ARCH_KEEP_MEMBLOCK not set, we expect to discard related > code and data. But it doesn't until CONFIG_MEMORY_HOTPLUG not set > neither. When CONFIG_ARCH_KEEP_MEMBLOCK is not set memblock information both for normal and reserved memory get freed up but should the memblock related code and data also be freed up as well ? Then I would also believe such memory saving will be very minimal given CONFIG_ARCH_KEEP_MEMBLOCK code is too limited scoped in the tree. Also could you please explain how it is related to CONFIG_MEMORY_HOTPLUG config being set or not. > > This patch puts memblock's .text/.data into its own section, so that it > only depends on CONFIG_ARCH_KEEP_MEMBLOCK to discard related code and > data. After this, init size increase from 2420K to 2432K. Is not this memory size saving some what insignificant to warrant a code change ? Also is this problem applicable only to CONFIG_ARCH_KEEP_MEMBLOCK config. Could you also provide details on how did you measure these numbers ? > > Signed-off-by: Wei Yang > --- > include/asm-generic/vmlinux.lds.h | 14 +++++++++++++- > include/linux/memblock.h | 8 ++++---- > 2 files changed, 17 insertions(+), 5 deletions(-) > > diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h > index f7749d0f2562..775c5eedb9e6 100644 > --- a/include/asm-generic/vmlinux.lds.h > +++ b/include/asm-generic/vmlinux.lds.h > @@ -147,6 +147,14 @@ > #define MEM_DISCARD(sec) *(.mem##sec) > #endif > > +#if defined(CONFIG_ARCH_KEEP_MEMBLOCK) > +#define MEMBLOCK_KEEP(sec) *(.mb##sec) > +#define MEMBLOCK_DISCARD(sec) > +#else > +#define MEMBLOCK_KEEP(sec) > +#define MEMBLOCK_DISCARD(sec) *(.mb##sec) > +#endif > + > #ifndef CONFIG_HAVE_DYNAMIC_FTRACE_NO_PATCHABLE > #define KEEP_PATCHABLE KEEP(*(__patchable_function_entries)) > #define PATCHABLE_DISCARDS > @@ -356,6 +364,7 @@ > *(.ref.data) \ > *(.data..shared_aligned) /* percpu related */ \ > MEM_KEEP(init.data*) \ > + MEMBLOCK_KEEP(init.data*) \ > *(.data.unlikely) \ > __start_once = .; \ > *(.data.once) \ > @@ -573,6 +582,7 @@ > *(.ref.text) \ > *(.text.asan.* .text.tsan.*) \ > MEM_KEEP(init.text*) \ > + MEMBLOCK_KEEP(init.text*) \ > > > /* sched.text is aling to function alignment to secure we have same > @@ -680,6 +690,7 @@ > KEEP(*(SORT(___kentry+*))) \ > *(.init.data .init.data.*) \ > MEM_DISCARD(init.data*) \ > + MEMBLOCK_DISCARD(init.data*) \ > KERNEL_CTORS() \ > MCOUNT_REC() \ > *(.init.rodata .init.rodata.*) \ > @@ -706,7 +717,8 @@ > #define INIT_TEXT \ > *(.init.text .init.text.*) \ > *(.text.startup) \ > - MEM_DISCARD(init.text*) > + MEM_DISCARD(init.text*) \ > + MEMBLOCK_DISCARD(init.text*) > > #define EXIT_DATA \ > *(.exit.data .exit.data.*) \ > diff --git a/include/linux/memblock.h b/include/linux/memblock.h > index e2082240586d..3e1f1d42dde7 100644 > --- a/include/linux/memblock.h > +++ b/include/linux/memblock.h > @@ -100,13 +100,13 @@ struct memblock { > > extern struct memblock memblock; > > +#define __init_memblock __section(".mbinit.text") __cold notrace \ > + __latent_entropy > +#define __initdata_memblock __section(".mbinit.data") > + > #ifndef CONFIG_ARCH_KEEP_MEMBLOCK > -#define __init_memblock __meminit > -#define __initdata_memblock __meminitdata > void memblock_discard(void); > #else > -#define __init_memblock > -#define __initdata_memblock > static inline void memblock_discard(void) {} > #endif >