Messages in this thread | | | Date | Thu, 1 Dec 2011 15:19:41 +0100 | From | Michal Hocko <> | Subject | Re: [PATCH 1/3] frv: remove irqsave pgd_lock locking |
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On Wed 09-11-11 16:47:17, 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: Andrea Arcangeli <aarcange@redhat.com> > --- > arch/frv/mm/pgalloc.c | 12 ++++-------- > 1 files changed, 4 insertions(+), 8 deletions(-) > > diff --git a/arch/frv/mm/pgalloc.c b/arch/frv/mm/pgalloc.c > index 4fb63a3..9df65c6 100644 > --- a/arch/frv/mm/pgalloc.c > +++ b/arch/frv/mm/pgalloc.c > @@ -104,10 +104,8 @@ 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_PGDS_IN_LAST_PML4, > swapper_pg_dir + USER_PGDS_IN_LAST_PML4, > @@ -117,18 +115,16 @@ void pgd_ctor(void *pgd) > return; > > pgd_list_add(pgd); > - spin_unlock_irqrestore(&pgd_lock, flags); > + spin_unlock(&pgd_lock); > memset(pgd, 0, USER_PGDS_IN_LAST_PML4 * 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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