提交 2fbfac4e 编写于 作者: H Hugh Dickins 提交者: Linus Torvalds

thp+memcg-numa: fix BUG at include/linux/mm.h:370!

THP's collapse_huge_page() has an understandable but ugly difference
in when its huge page is allocated: inside if NUMA but outside if not.
It's hardly surprising that the memcg failure path forgot that, freeing
the page in the non-NUMA case, then hitting a VM_BUG_ON in get_page()
(or even worse, using the freed page).
Signed-off-by: NHugh Dickins <hughd@google.com>
Reviewed-by: NMinchan Kim <minchan.kim@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
上级 c44ed965
......@@ -1762,6 +1762,10 @@ static void collapse_huge_page(struct mm_struct *mm,
#ifndef CONFIG_NUMA
VM_BUG_ON(!*hpage);
new_page = *hpage;
if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))) {
up_read(&mm->mmap_sem);
return;
}
#else
VM_BUG_ON(*hpage);
/*
......@@ -1781,12 +1785,12 @@ static void collapse_huge_page(struct mm_struct *mm,
*hpage = ERR_PTR(-ENOMEM);
return;
}
#endif
if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))) {
up_read(&mm->mmap_sem);
put_page(new_page);
return;
}
#endif
/* after allocating the hugepage upgrade to mmap_sem write mode */
up_read(&mm->mmap_sem);
......
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