Re: [PATCH v2 0/1] Fix slow loading problem introduced by 887f98f0d

[Gary Lin]

On Tue, Sep 13, 2022 at 01:49:51AM +0800, Zhang Boyang wrote:
> Hi,
> 
> This patch should probably fix the slow loading problem introduced by
> 887f98f0db43 (mm: Allow dynamically requesting additional memory
> regions).
> 
> Although I'm not against increasing default heap size, simply increasing
> heap size may not fully fix the problem. I think the root cause is disk
> caches are always invalidated when almost every malloc() after default
> heap size is exhausted.
> 
Deferring disk cache invalidation may not be a good idea because disk
cache is not mission-critical, so it's reasonable to invalidate the
caches to squeeze more memory blocks. The real question is still about
the default heap size. The memory allocation path is not cheap and it
should be avoided as much as possible. If the first allocated heap can
fulfill the most cases, then users won't be bothered by the performance
drop that much.

Gary Lin

> However, I havn't reproduced the problem, so I haven't tested my patch.
> I would appreciate if someone can test this patch.
> 
> Changes in V2:
>   Use GRUB_MM_HEAP_GROW constant instead of hardcoding 0x100000.
>   Renamed "rsize" to "grow".
>   Check "grow" against sanity limits.
> 
> Best Regards,
> Zhang Boyang 
> 
> 
>