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| author | Nicholas Piggin <npiggin@gmail.com> | 2023-02-03 08:18:35 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-03-29 01:20:08 +0200 |
| commit | 88e3009b5283bbd41447f0352d0b9df16cf6f183 (patch) | |
| tree | 8b1bd9f8227e2ded210820aede11453565397f4c /Documentation/mm/active_mm.rst | |
| parent | lazy tlb: introduce lazy tlb mm refcount helper functions (diff) | |
| download | linux-88e3009b5283bbd41447f0352d0b9df16cf6f183.tar.xz linux-88e3009b5283bbd41447f0352d0b9df16cf6f183.zip | |
lazy tlb: allow lazy tlb mm refcounting to be configurable
Add CONFIG_MMU_TLB_REFCOUNT which enables refcounting of the lazy tlb mm
when it is context switched. This can be disabled by architectures that
don't require this refcounting if they clean up lazy tlb mms when the last
refcount is dropped. Currently this is always enabled, so the patch
introduces no functional change.
Link: https://lkml.kernel.org/r/20230203071837.1136453-4-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'Documentation/mm/active_mm.rst')
| -rw-r--r-- | Documentation/mm/active_mm.rst | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/Documentation/mm/active_mm.rst b/Documentation/mm/active_mm.rst index 45d89f8fb3a8..d096fc091e23 100644 --- a/Documentation/mm/active_mm.rst +++ b/Documentation/mm/active_mm.rst @@ -2,6 +2,12 @@ Active MM ========= +Note, the mm_count refcount may no longer include the "lazy" users +(running tasks with ->active_mm == mm && ->mm == NULL) on kernels +with CONFIG_MMU_LAZY_TLB_REFCOUNT=n. Taking and releasing these lazy +references must be done with mmgrab_lazy_tlb() and mmdrop_lazy_tlb() +helpers, which abstract this config option. + :: List: linux-kernel |