The patch titled
mm: avoid tlb gather restarts
has been added to the -mm tree. Its filename is
mm-avoid-tlb-gather-restarts.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: mm: avoid tlb gather restarts
From: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
If need_resched() is false in the inner loop of unmap_vmas it is unnecessary
to do a full blown tlb_finish_mmu / tlb_gather_mmu for each ZAP_BLOCK_SIZE
ptes. Do a tlb_flush_mmu() instead. That gives architectures with a
non-generic tlb flush implementation room for optimization. The tlb_flush_mmu
primitive is a available with the generic tlb flush code, the
ia64_tlb_flush_mm needs to be renamed and a dummy function is added to arm and
arm26.
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Acked-by: Hugh Dickins <hugh@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/asm-arm/tlb.h | 5 +++++
include/asm-arm26/tlb.h | 5 +++++
include/asm-ia64/tlb.h | 6 +++---
mm/memory.c | 16 ++++++----------
4 files changed, 19 insertions(+), 13 deletions(-)
diff -puN include/asm-arm/tlb.h~mm-avoid-tlb-gather-restarts include/asm-arm/tlb.h
--- a/include/asm-arm/tlb.h~mm-avoid-tlb-gather-restarts
+++ a/include/asm-arm/tlb.h
@@ -52,6 +52,11 @@ tlb_gather_mmu(struct mm_struct *mm, uns
}
static inline void
+tlb_flush_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
+{
+}
+
+static inline void
tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
{
if (tlb->fullmm)
diff -puN include/asm-arm26/tlb.h~mm-avoid-tlb-gather-restarts include/asm-arm26/tlb.h
--- a/include/asm-arm26/tlb.h~mm-avoid-tlb-gather-restarts
+++ a/include/asm-arm26/tlb.h
@@ -29,6 +29,11 @@ tlb_gather_mmu(struct mm_struct *mm, uns
}
static inline void
+tlb_flush_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
+{
+}
+
+static inline void
tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
{
if (tlb->need_flush)
diff -puN include/asm-ia64/tlb.h~mm-avoid-tlb-gather-restarts include/asm-ia64/tlb.h
--- a/include/asm-ia64/tlb.h~mm-avoid-tlb-gather-restarts
+++ a/include/asm-ia64/tlb.h
@@ -72,7 +72,7 @@ DECLARE_PER_CPU(struct mmu_gather, mmu_g
* freed pages that where gathered up to this point.
*/
static inline void
-ia64_tlb_flush_mmu (struct mmu_gather *tlb, unsigned long start, unsigned long end)
+tlb_flush_mmu (struct mmu_gather *tlb, unsigned long start, unsigned long end)
{
unsigned int nr;
@@ -160,7 +160,7 @@ tlb_finish_mmu (struct mmu_gather *tlb,
* Note: tlb->nr may be 0 at this point, so we can't rely on tlb->start_addr and
* tlb->end_addr.
*/
- ia64_tlb_flush_mmu(tlb, start, end);
+ tlb_flush_mmu(tlb, start, end);
/* keep the page table cache within bounds */
check_pgt_cache();
@@ -184,7 +184,7 @@ tlb_remove_page (struct mmu_gather *tlb,
}
tlb->pages[tlb->nr++] = page;
if (tlb->nr >= FREE_PTE_NR)
- ia64_tlb_flush_mmu(tlb, tlb->start_addr, tlb->end_addr);
+ tlb_flush_mmu(tlb, tlb->start_addr, tlb->end_addr);
}
/*
diff -puN mm/memory.c~mm-avoid-tlb-gather-restarts mm/memory.c
--- a/mm/memory.c~mm-avoid-tlb-gather-restarts
+++ a/mm/memory.c
@@ -851,18 +851,15 @@ unsigned long unmap_vmas(struct mmu_gath
break;
}
- tlb_finish_mmu(*tlbp, tlb_start, start);
-
if (need_resched() ||
(i_mmap_lock && need_lockbreak(i_mmap_lock))) {
- if (i_mmap_lock) {
- *tlbp = NULL;
+ if (i_mmap_lock)
goto out;
- }
+ tlb_finish_mmu(*tlbp, tlb_start, start);
cond_resched();
- }
-
- *tlbp = tlb_gather_mmu(vma->vm_mm, fullmm);
+ *tlbp = tlb_gather_mmu(vma->vm_mm, fullmm);
+ } else
+ tlb_flush_mmu(*tlbp, tlb_start, start);
tlb_start_valid = 0;
zap_work = ZAP_BLOCK_SIZE;
}
@@ -890,8 +887,7 @@ unsigned long zap_page_range(struct vm_a
tlb = tlb_gather_mmu(mm, 0);
update_hiwater_rss(mm);
end = unmap_vmas(&tlb, vma, address, end, &nr_accounted, details);
- if (tlb)
- tlb_finish_mmu(tlb, address, end);
+ tlb_finish_mmu(tlb, address, end);
return end;
}
_
Patches currently in -mm which might be from schwidefsky@xxxxxxxxxx are
lots-of-architectures-enable-arbitary-speed-tty-support.patch
git-acpi-s390-struct-bin_attribute-changes.patch
git-s390.patch
s390-rename-cpu_idle-to-s390_cpu_idle.patch
scsi-dont-build-scsi_dma_mapunmap-for-has_dma.patch
scsi-dont-build-scsi_dma_mapunmap-for-has_dma-fix.patch
mm-avoid-tlb-gather-restarts.patch
mm-remove-ptep_establish.patch
mm-remove-ptep_test_and_clear_dirty-and-ptep_clear_flush_dirty.patch
mm-move-mm_struct-and-vm_area_struct.patch
dma-mapping-prevent-dma-dependent-code-from-linking-on.patch
generic-bug-use-show_regs-instead-of-dump_stack.patch
fallocate-implementation-on-i86-x86_64-and-powerpc.patch
fallocate-on-s390.patch
-
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