Messages in this thread | | | From | "Huang\, Ying" <> | Subject | Re: [PATCH -mm 06/21] mm, THP, swap: Support PMD swap mapping when splitting huge PMD | Date | Wed, 18 Apr 2018 08:38:16 +0800 |
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Randy Dunlap <rdunlap@infradead.org> writes:
> On 04/16/18 19:02, Huang, Ying wrote: >> From: Huang Ying <ying.huang@intel.com> >> >> A huge PMD need to be split when zap a part of the PMD mapping etc. >> If the PMD mapping is a swap mapping, we need to split it too. This >> patch implemented the support for this. This is similar as splitting >> the PMD page mapping, except we need to decrease the PMD swap mapping >> count for the huge swap cluster too. If the PMD swap mapping count >> becomes 0, the huge swap cluster will be split. >> >> Notice: is_huge_zero_pmd() and pmd_page() doesn't work well with swap >> PMD, so pmd_present() check is called before them. > > FWIW, I would prefer to see that comment in the source code, not just > in the commit description.
Sure. I will add comment in source code too.
Best Regards, Huang, Ying
>> >> Signed-off-by: "Huang, Ying" <ying.huang@intel.com> >> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> >> Cc: Andrea Arcangeli <aarcange@redhat.com> >> Cc: Michal Hocko <mhocko@suse.com> >> Cc: Johannes Weiner <hannes@cmpxchg.org> >> Cc: Shaohua Li <shli@kernel.org> >> Cc: Hugh Dickins <hughd@google.com> >> Cc: Minchan Kim <minchan@kernel.org> >> Cc: Rik van Riel <riel@redhat.com> >> Cc: Dave Hansen <dave.hansen@linux.intel.com> >> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> >> Cc: Zi Yan <zi.yan@cs.rutgers.edu> >> --- >> include/linux/swap.h | 6 +++++ >> mm/huge_memory.c | 54 ++++++++++++++++++++++++++++++++++++++++---- >> mm/swapfile.c | 28 +++++++++++++++++++++++ >> 3 files changed, 83 insertions(+), 5 deletions(-)
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