[PATCH 20/21] erofs: kill use_vmap module parameter

Gao Xiang gaoxiang25 at huawei.com
Mon Sep 2 12:43:19 UTC 2019


Hi Christoph,

On Mon, Sep 02, 2019 at 05:31:24AM -0700, Christoph Hellwig wrote:
> > @@ -224,9 +220,6 @@ static void *erofs_vmap(struct page **pages, unsigned int count)
> >  {
> >  	int i = 0;
> >  
> > -	if (use_vmap)
> > -		return vmap(pages, count, VM_MAP, PAGE_KERNEL);
> > -
> >  	while (1) {
> >  		void *addr = vm_map_ram(pages, count, -1, PAGE_KERNEL);
> 
> I think you can just open code this in the caller.

Yes, the only one user... will fix...

> 
> >  static void erofs_vunmap(const void *mem, unsigned int count)
> >  {
> > -	if (!use_vmap)
> > -		vm_unmap_ram(mem, count);
> > -	else
> > -		vunmap(mem);
> > +	vm_unmap_ram(mem, count);
> >  }
> 
> And this wrapper can go away entirely.

Got it. will fix.

> 
> And don't forget to report your performance observations to the arm64
> maintainers!

In my observation, vm_map_ram always performs better...
If there are something strange later, I will report to them
immediately... :)

Thanks,
Gao Xiang



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