mm, x86/mm: Make the batched unmap TLB flush API more generic
authorAndy Lutomirski <luto@kernel.org>
Mon, 22 May 2017 22:30:03 +0000 (15:30 -0700)
committerIngo Molnar <mingo@kernel.org>
Wed, 24 May 2017 08:18:27 +0000 (10:18 +0200)
commite73ad5ff2f76da25390e9607cb549691639330c3
treecb59d9a9fba1a6ee7463fa4114184b9f0c4ce8e2
parentb3b90e5af7976e46541f5029a369c9c38c5e4cea
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>
arch/x86/include/asm/tlbbatch.h [new file with mode: 0644]
arch/x86/include/asm/tlbflush.h
arch/x86/mm/tlb.c
include/linux/mm_types_task.h
mm/rmap.c