Re: [PATCH 1/7] ubi: block: Refactor sg list processing for highmem

From: Richard Weinberger
Date: Thu Aug 10 2023 - 15:54:59 EST


----- Ursprüngliche Mail -----
> Von: "Christoph Hellwig" <hch@xxxxxxxxxxxxx>
> An: "richard" <richard@xxxxxx>
> On Thu, Aug 10, 2023 at 06:15:36PM +0200, Richard Weinberger wrote:
>> >> The followup patches in this series will switch to kmap_sg()
>> >> and we can remove our own helper and the bounce buffer.
>> >
>> > Please just use kmap_local and avoid the bounce buffering.
>>
>> Patch 6 does this.
>
> But why add the bounce buffering first if you can avoid it from the
> very beginning by just using kmap_local instead of adding a new
> caller for the deprecate kmap_atomic?

Because I want this fix also in all stable trees. kmap_local() is rather
new. When back porting patch 1/7, bounce buffers and kmap_atomic()
are needed anyway.
By doing this in patch 1/7 I avoid backport troubles and keep the
delta between upstream and stable trees minimal.

Thanks,
//richard