• Gerald Schaefer's avatar
    hugetlbfs: add missing TLB flush to hugetlb_cow() · 8fe627ec
    Gerald Schaefer authored
    A cow break on a hugetlbfs page with page_count > 1 will set a new pte with
    set_huge_pte_at(), w/o any tlb flush operation.  The old pte will remain in
    the tlb and subsequent write access to the page will result in a page fault
    loop, for as long as it may take until the tlb is flushed from somewhere else.
     This patch introduces an architecture-specific huge_ptep_clear_flush()
    function, which is called before the the set_huge_pte_at() in hugetlb_cow().
    ATTENTION: This is just a nop on all architectures for now, the s390
    implementation will come with our large page patch later.  Other architectures
    should define their own huge_ptep_clear_flush() if needed.
    Acked-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
    Signed-off-by: default avatarGerald Schaefer <gerald.schaefer@de.ibm.com>
    Cc: Paul Mundt <lethal@linux-sh.org>
    Cc: "Luck, Tony" <tony.luck@intel.com>
    Cc: Ingo Molnar <mingo@elte.hu>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: "David S. Miller" <davem@davemloft.net>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>