The patch titled
Subject: mm, mmu_notifier: be explicit about range invalition non-blocking mode
has been added to the -mm tree. Its filename is
mm-mmu_notifier-be-explicit-about-range-invalition-non-blocking-mode.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-mmu_notifier-be-explicit-about-range-invalition-non-blocking-mode.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-mmu_notifier-be-explicit-about-range-invalition-non-blocking-mode.patch
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------------------------------------------------------
From: Michal Hocko <mhocko@xxxxxxxx>
Subject: mm, mmu_notifier: be explicit about range invalition non-blocking mode
If invalidate_range_start() is called for !blocking mode then all
callbacks have to guarantee they will no block/sleep. The same obviously
applies to invalidate_range_end because this operation pairs with the
former and they are called from the same context. Make sure this is
appropriately documented.
Link: http://lkml.kernel.org/r/20180827112623.8992-3-mhocko@xxxxxxxxxx
Signed-off-by: Michal Hocko <mhocko@xxxxxxxx>
Reviewed-by: Jerome Glisse <jglisse@xxxxxxxxxx>
Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Juergen Gross <jgross@xxxxxxxx>
Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/mmu_notifier.h | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/include/linux/mmu_notifier.h~mm-mmu_notifier-be-explicit-about-range-invalition-non-blocking-mode
+++ a/include/linux/mmu_notifier.h
@@ -153,7 +153,9 @@ struct mmu_notifier_ops {
*
* If blockable argument is set to false then the callback cannot
* sleep and has to return with -EAGAIN. 0 should be returned
- * otherwise.
+ * otherwise. Please note that if invalidate_range_start approves
+ * a non-blocking behavior then the same applies to
+ * invalidate_range_end.
*
*/
int (*invalidate_range_start)(struct mmu_notifier *mn,
_
Patches currently in -mm which might be from mhocko@xxxxxxxx are
mmpage_alloc-pf_wq_worker-threads-must-sleep-at-should_reclaim_retry.patch
xen-gntdev-fix-up-blockable-calls-to-mn_invl_range_start.patch
mm-mmu_notifier-be-explicit-about-range-invalition-non-blocking-mode.patch
revert-mm-mmu_notifier-annotate-mmu-notifiers-with-blockable-invalidate-callbacks.patch
