| From | "Kirill A. Shutemov" <> | Subject | Re: [PATCHv2, RFC 00/30] Transparent huge page cache | Date | Mon, 18 Mar 2013 13:19:39 +0200 (EET) |
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Simon Jeons wrote: > On 03/18/2013 12:03 PM, Simon Jeons wrote: > > Hi Kirill, > > On 03/15/2013 01:50 AM, Kirill A. Shutemov wrote: > >> From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> > >> > >> Here's the second version of the patchset. > >> > >> The intend of the work is get code ready to enable transparent huge page > >> cache for the most simple fs -- ramfs. > >> > >> We have read()/write()/mmap() functionality now. Still plenty work > >> ahead. > > > > One offline question. > > > > Why set PG_mlocked to page_tail which be splited in function > > __split_huge_page_refcount?
Not set, but copied from head page. Head page represents up-to-date sate of compound page, we need to copy it to all tail pages on split.
> Also why can't find where _PAGE_SPLITTING and _PAGE_PSE flags are > cleared in split_huge_page path?
The pmd is invalidated and replaced with reference to page table at the end of __split_huge_page_map.
> Another offline question: > Why don't clear tail page PG_tail flag in function > __split_huge_page_refcount?
We do:
page_tail->flags &= ~PAGE_FLAGS_CHECK_AT_PREP | __PG_HWPOISON;
-- Kirill A. Shutemov
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