linux/arch/um
Linus Torvalds 1cf35d4771 mm: split 'tlb_flush_mmu()' into tlb flushing and memory freeing parts
The mmu-gather operation 'tlb_flush_mmu()' has done two things: the
actual tlb flush operation, and the batched freeing of the pages that
the TLB entries pointed at.

This splits the operation into separate phases, so that the forced
batched flushing done by zap_pte_range() can now do the actual TLB flush
while still holding the page table lock, but delay the batched freeing
of all the pages to after the lock has been dropped.

This in turn allows us to avoid a race condition between
set_page_dirty() (as called by zap_pte_range() when it finds a dirty
shared memory pte) and page_mkclean(): because we now flush all the
dirty page data from the TLB's while holding the pte lock,
page_mkclean() will be held up walking the (recently cleaned) page
tables until after the TLB entries have been flushed from all CPU's.

Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Dave Hansen <dave.hansen@intel.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-25 16:05:40 -07:00
..
configs
drivers
include mm: split 'tlb_flush_mmu()' into tlb flushing and memory freeing parts 2014-04-25 16:05:40 -07:00
kernel um: Memory corruption on startup 2014-04-20 23:57:21 +02:00
os-Linux um: Memory corruption on startup 2014-04-20 23:57:21 +02:00
scripts
sys-ia64
sys-ppc
.gitignore
Kconfig.char
Kconfig.common
Kconfig.debug
Kconfig.net
Kconfig.rest
Kconfig.um
Makefile
Makefile-ia64
Makefile-os-Linux
Makefile-ppc
Makefile-skas