Re: [PATCH] mm/highmem: Align-down to page the address for kunmap_flush_on_unmap()

[Fabio M. De Francesco]

On giovedì 26 gennaio 2023 21:07:53 CET Matthew Wilcox wrote:
> On Thu, Jan 26, 2023 at 03:33:46PM +0100, Fabio M. De Francesco wrote:
> > If ARCH_HAS_FLUSH_ON_KUNMAP is defined (PA-RISC case), __kunmap_local()
> > calls kunmap_flush_on_unmap(). The latter currently flushes the wrong
> > address (as confirmed by Matthew Wilcox and Helge Deller). Al Viro
> > proposed to call kunmap_flush_on_unmap() on an aligned-down to page
> > address in order to fix this issue. Consensus has been reached on this
> > solution.
> > 
> > Therefore, if ARCH_HAS_FLUSH_ON_KUNMAP is defined, call
> > kunmap_flush_on_unmap() on an aligned-down to page address computed with
> > the PTR_ALIGN_DOWN() macro.
> 
> You missed a spot.  Sent the version I've had in my tree for a few days.

I'm sorry for missing the other call site.
Furthermore, your patch has a better commit message. 

However, I'm also sorry because I would have expected a different kind of 
support from you. My patch could have been improved with v2.

Anyway, I assume that you missed that I had asked you and Al if anybody were 
interested in doing these changes and probably you missed also that Ira 
encouraged me to send a patch, whereas you did not show any interest...
https://lore.kernel.org/lkml/3146373.5fSG56mABF@suse/

Fabio

P.S.: Helge wrote to me privately but you cannot know it.