Re: [PATCH 2/2] MIPS: Select ARCH_KEEP_MEMBLOCK to enable sysfs memblock debug

Thomas Bogendoerfer
2020-12-04T12:11:12Z

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.

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