arm64: mm: enable HAVE_RCU_TABLE_FREE logic
authorSteve Capper <steve.capper@linaro.org>
Thu, 9 Oct 2014 22:29:23 +0000 (15:29 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 10 Oct 2014 02:26:01 +0000 (22:26 -0400)
commit5e5f6dc10546f5c03bc572e3ba3089af30c66e2d
tree05c84c5be22dcb0bb752428dd4c726a0029bca8c
parentb8cd51afe05a98ef907e61c603d5c5b7ad6242d8
arm64: mm: enable HAVE_RCU_TABLE_FREE logic

In order to implement fast_get_user_pages we need to ensure that the page
table walker is protected from page table pages being freed from under it.

This patch enables HAVE_RCU_TABLE_FREE, any page table pages belonging to
address spaces with multiple users will be call_rcu_sched freed.  Meaning
that disabling interrupts will block the free and protect the fast gup
page walker.

Signed-off-by: Steve Capper <steve.capper@linaro.org>
Tested-by: Dann Frazier <dann.frazier@canonical.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
arch/arm64/Kconfig
arch/arm64/include/asm/tlb.h