diff options
| author | Andy Lutomirski <luto@kernel.org> | 2017-05-23 01:30:03 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-05-24 11:18:27 +0300 |
| commit | e73ad5ff2f76da25390e9607cb549691639330c3 (patch) | |
| tree | cb59d9a9fba1a6ee7463fa4114184b9f0c4ce8e2 /arch/x86/mm | |
| parent | b3b90e5af7976e46541f5029a369c9c38c5e4cea (diff) | |
| download | linux-e73ad5ff2f76da25390e9607cb549691639330c3.tar.xz | |
mm, x86/mm: Make the batched unmap TLB flush API more generic
try_to_unmap_flush() used to open-code a rather x86-centric flush
sequence: local_flush_tlb() + flush_tlb_others(). Rearrange the
code so that the arch (only x86 for now) provides
arch_tlbbatch_add_mm() and arch_tlbbatch_flush() and the core code
calls those functions instead.
I'll want this for x86 because, to enable address space ids, I can't
support the flush_tlb_others() mode used by exising
try_to_unmap_flush() implementation with good performance. I can
support the new API fairly easily, though.
I imagine that other architectures may be in a similar position.
Architectures with strong remote flush primitives (arm64?) may have
even worse performance problems with flush_tlb_others() the way that
try_to_unmap_flush() uses it.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Nadav Amit <namit@vmware.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/19f25a8581f9fb77876b7ff3b001f89835e34ea3.1495492063.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/mm')
| -rw-r--r-- | arch/x86/mm/tlb.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index 4d303864b310..743e4c6b4529 100644 --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -395,6 +395,23 @@ void flush_tlb_kernel_range(unsigned long start, unsigned long end) } } +void arch_tlbbatch_flush(struct arch_tlbflush_unmap_batch *batch) +{ + int cpu = get_cpu(); + + if (cpumask_test_cpu(cpu, &batch->cpumask)) { + count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ALL); + local_flush_tlb(); + trace_tlb_flush(TLB_LOCAL_SHOOTDOWN, TLB_FLUSH_ALL); + } + + if (cpumask_any_but(&batch->cpumask, cpu) < nr_cpu_ids) + flush_tlb_others(&batch->cpumask, NULL, 0, TLB_FLUSH_ALL); + cpumask_clear(&batch->cpumask); + + put_cpu(); +} + static ssize_t tlbflush_read_file(struct file *file, char __user *user_buf, size_t count, loff_t *ppos) { |