From: Nicholas Piggin <npiggin@gmail.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: Nicholas Piggin <npiggin@gmail.com>
Subject: [PATCH v3 4/7] powerpc/64s/radix: prefetch user address in update_mmu_cache
Date: Fri, 25 May 2018 03:58:50 +1000 [thread overview]
Message-ID: <20180524175853.19695-5-npiggin@gmail.com> (raw)
In-Reply-To: <20180524175853.19695-1-npiggin@gmail.com>
Prefetch the faulting address in update_mmu_cache to give the page
table walker perhaps 100 cycles head start as locks are dropped and
the interrupt completed.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/mm/mem.c | 4 +++-
arch/powerpc/mm/pgtable-book3s64.c | 3 ++-
2 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index c3c39b02b2ba..8cecda4bd66a 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -509,8 +509,10 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
*/
unsigned long access, trap;
- if (radix_enabled())
+ if (radix_enabled()) {
+ prefetch((void *)address);
return;
+ }
/* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
if (!pte_young(*ptep) || address >= TASK_SIZE)
diff --git a/arch/powerpc/mm/pgtable-book3s64.c b/arch/powerpc/mm/pgtable-book3s64.c
index 994492453f0e..7ce889a7e5ce 100644
--- a/arch/powerpc/mm/pgtable-book3s64.c
+++ b/arch/powerpc/mm/pgtable-book3s64.c
@@ -145,7 +145,8 @@ pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
void update_mmu_cache_pmd(struct vm_area_struct *vma, unsigned long addr,
pmd_t *pmd)
{
- return;
+ if (radix_enabled())
+ prefetch((void *)addr);
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
--
2.17.0
next prev parent reply other threads:[~2018-05-24 17:59 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-24 17:58 [PATCH v3 0/7] Various TLB and PTE improvements Nicholas Piggin
2018-05-24 17:58 ` [PATCH v3 1/7] powerpc/64s/radix: do not flush TLB when relaxing access Nicholas Piggin
2018-05-24 17:58 ` [PATCH v3 2/7] powerpc/64s/radix: do not flush TLB on spurious fault Nicholas Piggin
2018-05-24 17:58 ` [PATCH v3 3/7] powerpc/64s/radix: make ptep_get_and_clear_full non-atomic for the full case Nicholas Piggin
2018-05-24 17:58 ` Nicholas Piggin [this message]
2018-05-24 17:58 ` [PATCH v3 5/7] powerpc/64s/radix: avoid ptesync after set_pte and ptep_set_access_flags Nicholas Piggin
2018-05-24 17:58 ` [PATCH v3 6/7] powerpc/64s/radix: optimise pte_update Nicholas Piggin
2018-05-24 17:58 ` [PATCH v3 7/7] powerpc/64s/radix: flush remote CPUs out of single-threaded mm_cpumask Nicholas Piggin
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