Messages in this thread | | | Subject | Re: [PATCH v4 15/20] powerpc/mm: Avoid useless lock with single page fragments | From | Christophe LEROY <> | Date | Tue, 25 Sep 2018 18:49:07 +0200 |
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Le 19/09/2018 à 04:56, Aneesh Kumar K.V a écrit : > On 9/18/18 10:27 PM, Christophe Leroy wrote: >> There is no point in taking the page table lock as >> pte_frag is always NULL when we have only one fragment. >> >> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> >> --- >> arch/powerpc/mm/pgtable-frag.c | 3 +++ >> 1 file changed, 3 insertions(+) >> >> diff --git a/arch/powerpc/mm/pgtable-frag.c >> b/arch/powerpc/mm/pgtable-frag.c >> index bc924822dcd6..ab4910e92aaf 100644 >> --- a/arch/powerpc/mm/pgtable-frag.c >> +++ b/arch/powerpc/mm/pgtable-frag.c >> @@ -85,6 +85,9 @@ static pte_t *get_pte_from_cache(struct mm_struct *mm) >> { >> void *pte_frag, *ret; >> >> + if (PTE_FRAG_NR == 1) >> + return NULL; >> + >> spin_lock(&mm->page_table_lock); >> ret = mm->context.pte_frag; >> if (ret) { >> > > May be update get_pmd_from_cache too? >
Ok, done in v5
Christophe
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