From: Michal Hocko <mhocko@kernel.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
<linux-mm@kvack.org>, LKML <linux-kernel@vger.kernel.org>,
Michal Hocko <mhocko@suse.com>,
Jerome Glisse <jglisse@redhat.com>
Subject: [PATCH 2/3] mm, mmu_notifier: be explicit about range invalition non-blocking mode
Date: Mon, 27 Aug 2018 13:26:22 +0200 [thread overview]
Message-ID: <20180827112623.8992-3-mhocko@kernel.org> (raw)
In-Reply-To: <20180827112623.8992-1-mhocko@kernel.org>
From: Michal Hocko <mhocko@suse.com>
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.
Cc: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Michal Hocko <mhocko@suse.com>
---
include/linux/mmu_notifier.h | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
index 133ba78820ee..698e371aafe3 100644
--- a/include/linux/mmu_notifier.h
+++ b/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,
--
2.18.0
next prev parent reply other threads:[~2018-08-27 11:26 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-27 11:26 [PATCH 0/3] mmu_notifiers follow ups Michal Hocko
2018-08-27 11:26 ` [PATCH 1/3] xen/gntdev: fix up blockable calls to mn_invl_range_start Michal Hocko
2018-08-27 20:04 ` Boris Ostrovsky
2018-08-28 6:03 ` Juergen Gross
2018-08-27 11:26 ` Michal Hocko [this message]
2018-08-27 13:42 ` [PATCH 2/3] mm, mmu_notifier: be explicit about range invalition non-blocking mode Jerome Glisse
2018-08-27 11:26 ` [PATCH 3/3] Revert "mm, mmu_notifier: annotate mmu notifiers with blockable invalidate callbacks" Michal Hocko
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