From: Thomas Monjalon <thomas@monjalon.net>
To: Stephen Hemminger <stephen@networkplumber.org>
Cc: dev@dpdk.org, Tyler Retzlaff <roretzla@linux.microsoft.com>,
Chengwen Feng <fengchengwen@huawei.com>,
Anatoly Burakov <anatoly.burakov@intel.com>,
david.marchand@redhat.com, bruce.richardson@intel.com
Subject: Re: [PATCH v2] doc/eal: add signal safety warning
Date: Mon, 11 Jul 2022 23:15:26 +0200 [thread overview]
Message-ID: <3005473.57xzQst1vy@thomas> (raw)
In-Reply-To: <20220705204401.158650-1-stephen@networkplumber.org>
05/07/2022 22:44, Stephen Hemminger:
> 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>
> Acked-by: Tyler Retzlaff <roretzla@linux.microsoft.com>
> Acked-by: Chengwen Feng <fengchengwen@huawei.com>
> ---
> doc/guides/prog_guide/env_abstraction_layer.rst | 15 +++++++++++++++
> 1 file changed, 15 insertions(+)
>
> diff --git a/doc/guides/prog_guide/env_abstraction_layer.rst b/doc/guides/prog_guide/env_abstraction_layer.rst
> index 67842ae27207..de7ee92bba39 100644
> --- a/doc/guides/prog_guide/env_abstraction_layer.rst
> +++ b/doc/guides/prog_guide/env_abstraction_layer.rst
> @@ -818,6 +818,21 @@ Known Issues
>
> The debug statistics of rte_ring, rte_mempool and rte_timer are not supported in an unregistered non-EAL pthread.
>
> ++ signal safety
> +
> + The DPDK library is not designed to be async-signal-safe.
> + Except where explicitly stated otherwise [#]_, the DPDK functions are nonreentrant and are unsafe to call from a signal handler.
> +
> +.. [#] Only the function ``rte_dump_stack()`` can safely be called from signal handler in this version of DPDK.
Really? Are you sure?
Note: the use of [#] is probably limited to a single usage in the page?
> +
> +.. note::
> + The kinds of issues that make DPDK functions unsafe can be understood when
> + one considers that much of the code in DPDK uses locks and other shared
> + resources. If a device driver holding a ``rte_spinlock`` is interrupted
> + by a signal and control operation is then performed that would acquire
> + the same lock, a deadlock would result.
I find this note quite confusing.
next prev parent reply other threads:[~2022-07-11 21:15 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-10 15:23 [PATCH] " Stephen Hemminger
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 [this message]
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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=3005473.57xzQst1vy@thomas \
--to=thomas@monjalon.net \
--cc=anatoly.burakov@intel.com \
--cc=bruce.richardson@intel.com \
--cc=david.marchand@redhat.com \
--cc=dev@dpdk.org \
--cc=fengchengwen@huawei.com \
--cc=roretzla@linux.microsoft.com \
--cc=stephen@networkplumber.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).