Messages in this thread | | | Date | Thu, 1 Dec 2011 15:19:59 +0100 | From | Michal Hocko <> | Subject | Re: [PATCH 3/3] mn10300: remove irqsave pgd_lock locking |
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On Wed 09-11-11 16:47:19, Michal Hocko wrote: > a79e53d8: x86/mm: Fix pgd_lock deadlock dropped irqsave locking to fix a > deadlock. pgd_lock is not used from an irq context so we can drop > irqsave locking here as well. > The original patch was x86 only but the same applies here because both > pgd_ctor (aka mm_alloc_pgd) and pgd_dtor (aka mm_free_pgd) are not used > from an interrupt contexts. > > Signed-off-by: Michal Hocko <mhocko@suse.cz> > Cc: David Howells <dhowells@redhat.com> > Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com> > Cc: linux-am33-list@redhat.com > Cc: Andrea Arcangeli <aarcange@redhat.com> > --- > arch/mn10300/mm/pgtable.c | 12 ++++-------- > 1 files changed, 4 insertions(+), 8 deletions(-) > > diff --git a/arch/mn10300/mm/pgtable.c b/arch/mn10300/mm/pgtable.c > index 450f7ba..8e5e10d 100644 > --- a/arch/mn10300/mm/pgtable.c > +++ b/arch/mn10300/mm/pgtable.c > @@ -123,10 +123,8 @@ static inline void pgd_list_del(pgd_t *pgd) > > void pgd_ctor(void *pgd) > { > - unsigned long flags; > - > if (PTRS_PER_PMD == 1) > - spin_lock_irqsave(&pgd_lock, flags); > + spin_lock(&pgd_lock); > > memcpy((pgd_t *)pgd + USER_PTRS_PER_PGD, > swapper_pg_dir + USER_PTRS_PER_PGD, > @@ -136,18 +134,16 @@ void pgd_ctor(void *pgd) > return; > > pgd_list_add(pgd); > - spin_unlock_irqrestore(&pgd_lock, flags); > + spin_unlock(&pgd_lock); > memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t)); > } > > /* never called when PTRS_PER_PMD > 1 */ > void pgd_dtor(void *pgd) > { > - unsigned long flags; /* can be called from interrupt context */ > - > - spin_lock_irqsave(&pgd_lock, flags); > + spin_lock(&pgd_lock); > pgd_list_del(pgd); > - spin_unlock_irqrestore(&pgd_lock, flags); > + spin_unlock(&pgd_lock); > } > > pgd_t *pgd_alloc(struct mm_struct *mm) > -- > 1.7.7.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
-- Michal Hocko SUSE Labs SUSE LINUX s.r.o. Lihovarska 1060/12 190 00 Praha 9 Czech Republic
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