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| author | Peter Zijlstra <peterz@infradead.org> | 2020-02-04 02:37:11 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-02-04 04:05:26 +0100 |
| commit | 0d6e24d430ef23280d8dea0ba1faeefc66c26a57 (patch) | |
| tree | 6fb47b4bee252781c30105392a143e9a9a688903 /arch/Kconfig | |
| parent | asm-generic/tlb: rename HAVE_MMU_GATHER_NO_GATHER (diff) | |
| download | linux-0d6e24d430ef23280d8dea0ba1faeefc66c26a57.tar.xz linux-0d6e24d430ef23280d8dea0ba1faeefc66c26a57.zip | |
asm-generic/tlb: provide MMU_GATHER_TABLE_FREE
As described in the comment, the correct order for freeing pages is:
1) unhook page
2) TLB invalidate page
3) free page
This order equally applies to page directories.
Currently there are two correct options:
- use tlb_remove_page(), when all page directores are full pages and
there are no futher contraints placed by things like software
walkers (HAVE_FAST_GUP).
- use MMU_GATHER_RCU_TABLE_FREE and tlb_remove_table() when the
architecture does not do IPI based TLB invalidate and has
HAVE_FAST_GUP (or software TLB fill).
This however leaves architectures that don't have page based directories
but don't need RCU in a bind. For those, provide MMU_GATHER_TABLE_FREE,
which provides the independent batching for directories without the
additional RCU freeing.
Link: http://lkml.kernel.org/r/20200116064531.483522-10-aneesh.kumar@linux.ibm.com
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/Kconfig')
| -rw-r--r-- | arch/Kconfig | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/Kconfig b/arch/Kconfig index c35668fbf4d4..98de654b79b3 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -393,8 +393,12 @@ config HAVE_ARCH_JUMP_LABEL config HAVE_ARCH_JUMP_LABEL_RELATIVE bool +config MMU_GATHER_TABLE_FREE + bool + config MMU_GATHER_RCU_TABLE_FREE bool + select MMU_GATHER_TABLE_FREE config MMU_GATHER_PAGE_SIZE bool @@ -404,6 +408,7 @@ config MMU_GATHER_NO_RANGE config MMU_GATHER_NO_GATHER bool + depends on MMU_GATHER_TABLE_FREE config ARCH_HAVE_NMI_SAFE_CMPXCHG bool |