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| author | Andrea Arcangeli <aarcange@redhat.com> | 2011-02-16 15:45:22 -0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2011-03-10 09:41:57 +0100 |
| commit | a79e53d85683c6dd9f99c90511028adc2043031f (patch) | |
| tree | 191f423331b608a5f7f134f484ce62a9ee7fb4a6 /arch/x86/mm/pgtable.c | |
| parent | f86268549f424f83b9eb0963989270e14fbfc3de (diff) | |
| download | op-kernel-dev-a79e53d85683c6dd9f99c90511028adc2043031f.zip op-kernel-dev-a79e53d85683c6dd9f99c90511028adc2043031f.tar.gz | |
x86/mm: Fix pgd_lock deadlock
It's forbidden to take the page_table_lock with the irq disabled
or if there's contention the IPIs (for tlb flushes) sent with
the page_table_lock held will never run leading to a deadlock.
Nobody takes the pgd_lock from irq context so the _irqsave can be
removed.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: <stable@kernel.org>
LKML-Reference: <201102162345.p1GNjMjm021738@imap1.linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/mm/pgtable.c')
| -rw-r--r-- | arch/x86/mm/pgtable.c | 11 |
1 files changed, 4 insertions, 7 deletions
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c index 500242d..0113d19 100644 --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -121,14 +121,12 @@ static void pgd_ctor(struct mm_struct *mm, pgd_t *pgd) static void pgd_dtor(pgd_t *pgd) { - unsigned long flags; /* can be called from interrupt context */ - if (SHARED_KERNEL_PMD) return; - spin_lock_irqsave(&pgd_lock, flags); + spin_lock(&pgd_lock); pgd_list_del(pgd); - spin_unlock_irqrestore(&pgd_lock, flags); + spin_unlock(&pgd_lock); } /* @@ -260,7 +258,6 @@ pgd_t *pgd_alloc(struct mm_struct *mm) { pgd_t *pgd; pmd_t *pmds[PREALLOCATED_PMDS]; - unsigned long flags; pgd = (pgd_t *)__get_free_page(PGALLOC_GFP); @@ -280,12 +277,12 @@ pgd_t *pgd_alloc(struct mm_struct *mm) * respect to anything walking the pgd_list, so that they * never see a partially populated pgd. */ - spin_lock_irqsave(&pgd_lock, flags); + spin_lock(&pgd_lock); pgd_ctor(mm, pgd); pgd_prepopulate_pmd(mm, pgd, pmds); - spin_unlock_irqrestore(&pgd_lock, flags); + spin_unlock(&pgd_lock); return pgd; |
