| Message ID | 1606965544-22611-3-git-send-email-yangtiezhu@loongson.cn (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | memblock debug | expand |
在 2020/12/3 上午11:19, Tiezhu Yang 写道: > In the current code, CONFIG_ARCH_KEEP_MEMBLOCK is not set for MIPS arch, > memblock_discard() will discard memory and reserved arrays if they were > allocated, select ARCH_KEEP_MEMBLOCK to give a chance to track "memory" > and "reserved" memblocks after early boot, with this patch, we can see > the following two sysfs interfaces under DEBUG_FS. > > /sys/kernel/debug/memblock/memory > /sys/kernel/debug/memblock/reserved Is this really necessary? memblock data is not really necessary after boot for non-debug purpose. Given that MIPS is widely used in embedded systems which doesn't have much memory, keeping unused data after boot is kinda unconvincing. If you intend to debug that please do it locally. Thanks. - Jiaxun > > Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> > --- > arch/mips/Kconfig | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig > index 44a47ad..f65da197 100644 > --- a/arch/mips/Kconfig > +++ b/arch/mips/Kconfig > @@ -9,6 +9,7 @@ config MIPS > select ARCH_HAS_PTE_SPECIAL if !(32BIT && CPU_HAS_RIXI) > select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST > select ARCH_HAS_UBSAN_SANITIZE_ALL > + select ARCH_KEEP_MEMBLOCK > select ARCH_SUPPORTS_UPROBES > select ARCH_USE_BUILTIN_BSWAP > select ARCH_USE_CMPXCHG_LOCKREF if 64BIT
On Thu, Dec 03, 2020 at 11:58:51AM +0800, Jiaxun Yang wrote: > > > 在 2020/12/3 上午11:19, Tiezhu Yang 写道: > > In the current code, CONFIG_ARCH_KEEP_MEMBLOCK is not set for MIPS arch, > > memblock_discard() will discard memory and reserved arrays if they were > > allocated, select ARCH_KEEP_MEMBLOCK to give a chance to track "memory" > > and "reserved" memblocks after early boot, with this patch, we can see > > the following two sysfs interfaces under DEBUG_FS. > > > > /sys/kernel/debug/memblock/memory > > /sys/kernel/debug/memblock/reserved > > Is this really necessary? > memblock data is not really necessary after boot for non-debug purpose. > > Given that MIPS is widely used in embedded systems which doesn't have much > memory, keeping unused data after boot is kinda unconvincing. about how much memory are talking here ? > > If you intend to debug that please do it locally. maybe we can add a if DEBUG_KERNEL since enabling DEBUG_KERNEL will cost already some memory... Thomas.
On 12/04/2020 08:08 PM, Thomas Bogendoerfer wrote: > On Thu, Dec 03, 2020 at 11:58:51AM +0800, Jiaxun Yang wrote: >> >> 在 2020/12/3 上午11:19, Tiezhu Yang 写道: >>> In the current code, CONFIG_ARCH_KEEP_MEMBLOCK is not set for MIPS arch, >>> memblock_discard() will discard memory and reserved arrays if they were >>> allocated, select ARCH_KEEP_MEMBLOCK to give a chance to track "memory" >>> and "reserved" memblocks after early boot, with this patch, we can see >>> the following two sysfs interfaces under DEBUG_FS. >>> >>> /sys/kernel/debug/memblock/memory >>> /sys/kernel/debug/memblock/reserved >> Is this really necessary? >> memblock data is not really necessary after boot for non-debug purpose. >> >> Given that MIPS is widely used in embedded systems which doesn't have much >> memory, keeping unused data after boot is kinda unconvincing. > about how much memory are talking here ? > >> If you intend to debug that please do it locally. > maybe we can add a > > if DEBUG_KERNEL > > since enabling DEBUG_KERNEL will cost already some memory... Yes, that makes sense. If nobody has any objections, I will send v2 in the next week. Thanks, Tiezhu > > Thomas. >
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index 44a47ad..f65da197 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -9,6 +9,7 @@ config MIPS select ARCH_HAS_PTE_SPECIAL if !(32BIT && CPU_HAS_RIXI) select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST select ARCH_HAS_UBSAN_SANITIZE_ALL + select ARCH_KEEP_MEMBLOCK select ARCH_SUPPORTS_UPROBES select ARCH_USE_BUILTIN_BSWAP select ARCH_USE_CMPXCHG_LOCKREF if 64BIT
In the current code, CONFIG_ARCH_KEEP_MEMBLOCK is not set for MIPS arch, memblock_discard() will discard memory and reserved arrays if they were allocated, select ARCH_KEEP_MEMBLOCK to give a chance to track "memory" and "reserved" memblocks after early boot, with this patch, we can see the following two sysfs interfaces under DEBUG_FS. /sys/kernel/debug/memblock/memory /sys/kernel/debug/memblock/reserved Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> --- arch/mips/Kconfig | 1 + 1 file changed, 1 insertion(+)