[PATCH] erofs(shrinker): return SHRINK_EMPTY if no objects to free

[Chen Linxuan]

On Thu, 2025-01-16 at 16:45 +0800, Gao Xiang wrote:
> 
> On 2025/1/16 16:24, Chen Linxuan wrote:
> > On Thu, 2025-01-16 at 15:51 +0800, Gao Xiang wrote:
> > > Hi Linxuan,
> > > 
> > > On 2025/1/16 15:20, Chen Linxuan wrote:
> > > > Comments in file include/linux/shrinker.h says that
> > > > `count_objects` of `struct shrinker` should return SHRINK_EMPTY
> > > > when there are no objects to free.
> > > > 
> > > > > If there are no objects to free, it should return SHRINK_EMPTY,
> > > > > while 0 is returned in cases of the number of freeable items cannot
> > > > > be determined or shrinker should skip this cache for this time
> > > > > (e.g., their number is below shrinkable limit).
> > > 
> > > Thanks for the patch!
> > > 
> > > Yeah, it seems that is the case.  Yet it'd better to document
> > > what the impact if 0 is returned here if you know more..
> > 
> > Sorry, I have no idea about that.
> 
> I guess it has no difference if the shrinker is not memcg-aware,
> see:
> https://lore.kernel.org/r/153063070859.1818.11870882950920963480.stgit@localhost.localdomain
> 
> But I'm fine to use SHRINK_EMPTY since it's clearly documented.
> 
> So could you resend a patch to address my suggestion?

v2 patch has been sent.

> 
> Thanks,
> Gao Xiang
> 
>