[PATCH man-pages 4/5] userfaultfd.2: add note about asynchronios events delivery

From	Mike Rapoport <rppt@linux.vnet.ibm.com>
Newsgroups	linux.kernel
Subject	[PATCH man-pages 4/5] userfaultfd.2: add note about asynchronios events delivery
Date	2017-05-01 07:50 +0200
Message-ID	<tCcnD-51S-9@gated-at.bofh.it> (permalink)
References	<tCcnD-51S-3@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
---
 man2/userfaultfd.2 | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/man2/userfaultfd.2 b/man2/userfaultfd.2
index 8b89162..f177bba 100644
--- a/man2/userfaultfd.2
+++ b/man2/userfaultfd.2
@@ -112,6 +112,18 @@ created for the child process,
 which allows userfaultfd monitor to perform user-space paging
 for the child process.
 
+Unlike page faults which have to be synchronous and require
+explicit or implicit wakeup,
+all other events are delivered asynchronously and
+the non-cooperative process resumes execution as
+soon as manager executes
+.BR read(2).
+The userfaultfd manager should carefully synchronize calls
+to UFFDIO_COPY with the events processing.
+
+The current asynchronous model of the event delivery is optimal for
+single threaded non-cooperative userfaultfd manager implementations.
+
 .\" FIXME elaborate about non-cooperating mode, describe its limitations
 .\" for kernels before 4.11, features added in 4.11
 .\" and limitations remaining in 4.11
-- 
1.9.1

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[PATCH man-pages 4/5] userfaultfd.2: add note about asynchronios events delivery Mike Rapoport <rppt@linux.vnet.ibm.com> - 2017-05-01 07:50 +0200
  Re: [PATCH man-pages 4/5] userfaultfd.2: add note about asynchronios  events delivery "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com> - 2017-05-01 20:40 +0200
    Re: [PATCH man-pages 4/5] userfaultfd.2: add note about asynchronios  events delivery Mike Rapoport <rppt@linux.vnet.ibm.com> - 2017-05-02 11:50 +0200
      Re: [PATCH man-pages 4/5] userfaultfd.2: add note about asynchronios  events delivery "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com> - 2017-05-02 22:30 +0200

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