Messages in this thread | | | Date | Fri, 20 Oct 2017 15:18:07 +0300 | From | "Kirill A. Shutemov" <> | Subject | Re: [PATCH 0/6] Boot-time switching between 4- and 5-level paging for 4.15, Part 1 |
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On Fri, Oct 20, 2017 at 02:49:13AM -0700, Minchan Kim wrote: > Hi Ingo, > > On Fri, Oct 20, 2017 at 10:18:53AM +0200, Ingo Molnar wrote: > > > > * Kirill A. Shutemov <kirill@shutemov.name> wrote: > > > > > On Tue, Oct 03, 2017 at 11:27:54AM +0300, Kirill A. Shutemov wrote: > > > > On Fri, Sep 29, 2017 at 05:08:15PM +0300, Kirill A. Shutemov wrote: > > > > > The first bunch of patches that prepare kernel to boot-time switching > > > > > between paging modes. > > > > > > > > > > Please review and consider applying. > > > > > > > > Ping? > > > > > > Ingo, is there anything I can do to get review easier for you? > > > > Yeah, what is the conclusion on the sub-discussion of patch #2: > > > > [PATCH 2/6] mm/zsmalloc: Prepare to variable MAX_PHYSMEM_BITS > > > > ... do we want to skip it entirely and use the other 5 patches? > > Sorry for the too much late reply, Kirill. > Yes, you can skip it. > > As Nitin said in that patch's thread, zsmalloc has assumed > PFN_BIT is (BITS_PER_LONG - PAGE_SHIFT) so it already covers > X86_5LEVEL well, I think. > > In summary, there is no need to change it. > I hope it helps to merge this patchset series.
Acctually, no, we need something.
The problem is that later in the series[1] we make MAX_PHYSMEM_BITS dynamic. It's not a simple constant anymore.
But zsmalloc uses it to define _PFN_BIT, which, with few hoops, defines ZS_SIZE_CLASSES. ZS_SIZE_CLASSES is used to specify size of a field in 'struct zs_pool' and build fails if it's not constant.
My patch addresses this, but there are more than one solution to the problem.
Which way do you prefer to get it fixed?
[1] https://git.kernel.org/pub/scm/linux/kernel/git/kas/linux.git/commit/?h=la57/boot-switching/v8&id=57f669244fab9081a4343b59373ff43170ef328f
-- Kirill A. Shutemov
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