On Tue, May 21, 2024 at 10:21:52AM +0300, Mike Rapoport wrote:
>Hi,
>
>On Fri, May 10, 2024 at 02:04:22AM +0000, 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.
>>
>> 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, from the log message in mem_init_print_info(), init size
>> increase from 2420K to 2432K on arch x86.
>>
>> Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx>
>>
>> ---
>> v2: fix orphan section for powerpc
>> ---
>> arch/powerpc/kernel/vmlinux.lds.S | 1 +
>> include/asm-generic/vmlinux.lds.h | 14 +++++++++++++-
>> include/linux/memblock.h | 8 ++++----
>> 3 files changed, 18 insertions(+), 5 deletions(-)
>>
>> +#define __init_memblock __section(".mbinit.text") __cold notrace \
>> + __latent_entropy
>> +#define __initdata_memblock __section(".mbinit.data")
>> +
>
>The new .mbinit.* sections should be added to scripts/mod/modpost.c
>alongside .meminit.* sections and then I expect modpost to report a bunch
>of section mismatches because many memblock functions are called on memory
>hotplug even on architectures that don't select ARCH_KEEP_MEMBLOCK.
>
I tried to add some code in modpost.c, "make all" looks good.
May I ask how can I trigger the "mismatch" warning?
BTW, if ARCH_KEEP_MEMBLOCK unset, we would discard memblock meta-data. If
hotplug would call memblock function, it would be dangerous?
The additional code I used is like below.
---
scripts/mod/modpost.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 937294ff164f..c837e2882904 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -777,14 +777,14 @@ static void check_section(const char *modname, struct elf_info *elf,
#define ALL_INIT_DATA_SECTIONS \
".init.setup", ".init.rodata", ".meminit.rodata", \
- ".init.data", ".meminit.data"
+ ".init.data", ".meminit.data", "mbinit.data"
#define ALL_PCI_INIT_SECTIONS \
".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \
".pci_fixup_enable", ".pci_fixup_resume", \
".pci_fixup_resume_early", ".pci_fixup_suspend"
-#define ALL_XXXINIT_SECTIONS ".meminit.*"
+#define ALL_XXXINIT_SECTIONS ".meminit.*", "mbinit.*"
#define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
#define ALL_EXIT_SECTIONS ".exit.*"
@@ -799,7 +799,7 @@ static void check_section(const char *modname, struct elf_info *elf,
#define INIT_SECTIONS ".init.*"
-#define ALL_TEXT_SECTIONS ".init.text", ".meminit.text", ".exit.text", \
+#define ALL_TEXT_SECTIONS ".init.text", ".meminit.text", ".mbinit.text", ".exit.text", \
TEXT_SECTIONS, OTHER_TEXT_SECTIONS
enum mismatch {
--
2.34.1
>> #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
>>
>> --
>> 2.34.1
>>
>>
>
>--
>Sincerely yours,
>Mike.
--
Wei Yang
Help you, Help me
