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mm: page_alloc: use the correct THP order for THP PCP 

Commit 44042b4498 ("mm/page_alloc: allow high-order pages to be stored
on the per-cpu lists") extends the PCP allocator to store THP pages, and
it determines whether to cache THP pages in PCP by comparing with
pageblock_order.  But the pageblock_order is not always equal to THP
order.  It might also be MAX_PAGE_ORDER, which could prevent PCP from
caching THP pages.

Therefore, using HPAGE_PMD_ORDER instead to determine the need for caching
THP for PCP will fix this issue

Link: https://lkml.kernel.org/r/a25c9e14cd03907d5978b60546a69e6aa3fc2a7d.1712151833.git.baolin.wang@linux.alibaba.com
Fixes: 44042b4498 ("mm/page_alloc: allow high-order pages to be stored on the per-cpu lists")
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Barry Song <baohua@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Baolin Wang 2024-04-03 21:47:21 +08:00 committed by Andrew Morton
parent 039d26d10d
commit 6303d1c553
1 changed files with 3 additions and 3 deletions
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6
mm/page_alloc.c
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@ -506,7 +506,7 @@ static inline unsigned int order_to_pindex(int migratetype, int order)
{
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
if (order > PAGE_ALLOC_COSTLY_ORDER) {
VM_BUG_ON(order != pageblock_order);
VM_BUG_ON(order != HPAGE_PMD_ORDER);
return NR_LOWORDER_PCP_LISTS;
}
#else
@ -522,7 +522,7 @@ static inline int pindex_to_order(unsigned int pindex)
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
if (pindex == NR_LOWORDER_PCP_LISTS)
order = pageblock_order;
order = HPAGE_PMD_ORDER;
#else
VM_BUG_ON(order > PAGE_ALLOC_COSTLY_ORDER);
#endif
@ -535,7 +535,7 @@ static inline bool pcp_allowed_order(unsigned int order)
if (order <= PAGE_ALLOC_COSTLY_ORDER)
return true;
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
if (order == pageblock_order)
if (order == HPAGE_PMD_ORDER)
return true;
#endif
return false;