]> Gitweb @ Texas Instruments - Open Source Git Repositories - git.TI.com/gitweb - ti-linux-kernel/ti-linux-kernel.git/commit
mm/tlb: Remove tlb_remove_table() non-concurrent condition
authorPeter Zijlstra <peterz@infradead.org>
Wed, 22 Aug 2018 15:30:14 +0000 (17:30 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sun, 9 Sep 2018 18:04:34 +0000 (20:04 +0200)
commit70201a4e368833c15625d8dc32fd9c0286a12b58
tree5c2b2ec7cbf35248b7c2a45a69f0b26c3373ec26
parent2f04971a962949099881dfc7be23392ad14aa8c9
mm/tlb: Remove tlb_remove_table() non-concurrent condition

commit a6f572084fbee8b30f91465f4a085d7a90901c57 upstream.

Will noted that only checking mm_users is incorrect; we should also
check mm_count in order to cover CPUs that have a lazy reference to
this mm (and could do speculative TLB operations).

If removing this turns out to be a performance issue, we can
re-instate a more complete check, but in tlb_table_flush() eliding the
call_rcu_sched().

Fixes: 267239116987 ("mm, powerpc: move the RCU page-table freeing into generic code")
Reported-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Rik van Riel <riel@surriel.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: David Miller <davem@davemloft.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mm/memory.c