Re: [PATCH v8 20/24] erofs: introduce generic decompression backend

Gao Xiang
2019-08-30T16:53:13Z

Hi Christoph,

On Fri, Aug 30, 2019 at 09:35:34AM -0700, Christoph Hellwig wrote:
> On Thu, Aug 15, 2019 at 12:41:51PM +0800, Gao Xiang wrote:
> > +static bool use_vmap;
> > +module_param(use_vmap, bool, 0444);
> > +MODULE_PARM_DESC(use_vmap, "Use vmap() instead of vm_map_ram() (default 0)");
>
> And how would anyone know which to pick?

It has significant FIO benchmark difference on sequential read least on arm64...
I have no idea whether all platform vm_map_ram() behaves better than vmap(),
so I leave an option for users here...

Thanks,
Gao Xiang