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From: Stephen Hemminger <stephen@networkplumber.org>
To: dev@dpdk.org
Cc: anatoly.burakov@intel.com,
	Stephen Hemminger <stephen@networkplumber.org>
Subject: [PATCH] doc/eal: add signal safety warning
Date: Fri, 10 Jun 2022 08:23:43 -0700	[thread overview]
Message-ID: <20220610152343.38455-1-stephen@networkplumber.org> (raw)

The DPDK is not designed to be used from a signal handler.
Add a notice in the documentation describing this limitation,
similar to Linux signal-safety manual page.

Bugzilla ID: 1030
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
 doc/guides/prog_guide/env_abstraction_layer.rst | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/doc/guides/prog_guide/env_abstraction_layer.rst b/doc/guides/prog_guide/env_abstraction_layer.rst
index 5f0748fba1c0..36ab4b5ba9b6 100644
--- a/doc/guides/prog_guide/env_abstraction_layer.rst
+++ b/doc/guides/prog_guide/env_abstraction_layer.rst
@@ -732,6 +732,19 @@ controlled with tools like taskset (Linux) or cpuset (FreeBSD),
 - with affinity restricted to 2-3, the Control Threads will end up on
   CPU 2 (main lcore, which is the default when no CPU is available).
 
+Signal Safety
+~~~~~~~~~~~~~
+
+The DPDK functions in general can not be safely called from a signal handler.
+Most functions are not async-signal-safe because they can acquire locks
+and other resources that make them nonrentrant.
+
+To avoid problems with unsafe functions, can be avoided if required
+signals are blocked and a mechanism such as signalfd (Linux) is used
+to convert the asynchronous signals into messages that are processed
+by a EAL thread.
+
+
 .. _known_issue_label:
 
 Known Issues
-- 
2.35.1


             reply	other threads:[~2022-06-10 15:23 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-06-10 15:23 Stephen Hemminger [this message]
2022-06-10 22:53 ` Tyler Retzlaff
2022-06-10 23:38   ` Stephen Hemminger
2022-06-10 23:42 ` Tyler Retzlaff
2022-06-11  1:37   ` fengchengwen
2022-06-11 16:50 ` Mattias Rönnblom
2022-07-05 20:44 ` [PATCH v2] " Stephen Hemminger
2022-07-11 21:15   ` Thomas Monjalon
2022-07-11 21:31     ` Stephen Hemminger
2022-10-21 19:58     ` Stephen Hemminger
2022-07-11 23:02   ` [PATCH v3] " Stephen Hemminger
2022-07-11 23:04   ` [PATCH v4] " Stephen Hemminger
2022-11-09 23:17     ` Stephen Hemminger
2022-11-15 16:21     ` David Marchand

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