| Message ID | 20240830080020.33666-1-rongqianfeng@vivo.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | arm64/mm: Delete __init region from memblock.reserved | expand |
Hi Rong, On Fri, 30 Aug 2024 at 10:00, Rong Qianfeng <rongqianfeng@vivo.com> wrote: > > If CONFIG_ARCH_KEEP_MEMBLOCK is enabled, the memory information in > memblock will be retained. We release the __init memory here, and > we should also delete the corresponding region in memblock.reserved. > > Signed-off-by: Rong Qianfeng <rongqianfeng@vivo.com> > --- > arch/arm64/mm/init.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c > index bfb10969cbf0..99cfa217e905 100644 > --- a/arch/arm64/mm/init.c > +++ b/arch/arm64/mm/init.c > @@ -402,6 +402,13 @@ void __init mem_init(void) > > void free_initmem(void) > { > + if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) { This is always true on arm64 > + unsigned long aligned_begin = ALIGN_DOWN((u64)__init_begin, PAGE_SIZE); > + unsigned long aligned_end = ALIGN((u64)__init_end, PAGE_SIZE); > + > + memblock_free((void *)aligned_begin, aligned_end - aligned_begin); > + } > + What does this achieve? The memory is already being reused by the page allocator (due to free_reserved_area()), and the memblock allocator is no longer usable at this point anyway. > free_reserved_area(lm_alias(__init_begin), > lm_alias(__init_end), > POISON_FREE_INITMEM, "unused kernel");
在 2024/8/30 16:14, Ard Biesheuvel 写道: > Hi Rong, > > On Fri, 30 Aug 2024 at 10:00, Rong Qianfeng <rongqianfeng@vivo.com> wrote: >> If CONFIG_ARCH_KEEP_MEMBLOCK is enabled, the memory information in >> memblock will be retained. We release the __init memory here, and >> we should also delete the corresponding region in memblock.reserved. >> >> Signed-off-by: Rong Qianfeng <rongqianfeng@vivo.com> >> --- >> arch/arm64/mm/init.c | 7 +++++++ >> 1 file changed, 7 insertions(+) >> >> diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c >> index bfb10969cbf0..99cfa217e905 100644 >> --- a/arch/arm64/mm/init.c >> +++ b/arch/arm64/mm/init.c >> @@ -402,6 +402,13 @@ void __init mem_init(void) >> >> void free_initmem(void) >> { >> + if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) { > This is always true on arm64 > >> + unsigned long aligned_begin = ALIGN_DOWN((u64)__init_begin, PAGE_SIZE); >> + unsigned long aligned_end = ALIGN((u64)__init_end, PAGE_SIZE); >> + >> + memblock_free((void *)aligned_begin, aligned_end - aligned_begin); >> + } >> + > What does this achieve? The memory is already being reused by the page > allocator (due to free_reserved_area()), and the memblock allocator is > no longer usable at this point anyway. If not, incorrect information will be visible in /sys/kernel/debug/memblock/reserved. Best Regards, Qianfeng > >> free_reserved_area(lm_alias(__init_begin), >> lm_alias(__init_end), >> POISON_FREE_INITMEM, "unused kernel");
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index bfb10969cbf0..99cfa217e905 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -402,6 +402,13 @@ void __init mem_init(void) void free_initmem(void) { + if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) { + unsigned long aligned_begin = ALIGN_DOWN((u64)__init_begin, PAGE_SIZE); + unsigned long aligned_end = ALIGN((u64)__init_end, PAGE_SIZE); + + memblock_free((void *)aligned_begin, aligned_end - aligned_begin); + } + free_reserved_area(lm_alias(__init_begin), lm_alias(__init_end), POISON_FREE_INITMEM, "unused kernel");
If CONFIG_ARCH_KEEP_MEMBLOCK is enabled, the memory information in memblock will be retained. We release the __init memory here, and we should also delete the corresponding region in memblock.reserved. Signed-off-by: Rong Qianfeng <rongqianfeng@vivo.com> --- arch/arm64/mm/init.c | 7 +++++++ 1 file changed, 7 insertions(+)