From: Bagas Sanjaya <bagasdotme@gmail.com>
To: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Linux Documentation <linux-doc@vger.kernel.org>,
Linux Serial <linux-serial@vger.kernel.org>
Cc: "Jonathan Corbet" <corbet@lwn.net>,
"Cengiz Can" <cengiz@kernel.wtf>,
"Bagas Sanjaya" <bagasdotme@gmail.com>,
"Tomas Mudrunka" <tomas.mudrunka@gmail.com>,
"Jiri Slaby" <jirislaby@kernel.org>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
"Anselm Schüler" <mail@anselmschueler.com>,
"Randy Dunlap" <rdunlap@infradead.org>
Subject: [PATCH v2] Documentation: sysrq: Rewrite /proc/sysrq-trigger usage
Date: Thu, 16 Oct 2025 17:36:10 +0700 [thread overview]
Message-ID: <20251016103609.33897-2-bagasdotme@gmail.com> (raw)
/proc/sysrq-trigger usage documentation (in "On all" section) states
that it is not recommended to write extra characters to it to avoid
undefined behavior, which is contradictive to previous sentence that
such characters are ignored. Also, in order to actually process them
(as a string), prepending it with underscore is required.
Rewrite the description.
Link: https://lore.kernel.org/lkml/7ca05672-dc20-413f-a923-f77ce0a9d307@anselmschueler.com/
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
---
Changes since v1 [1]:
- Rewrite the whole "On all" section (Jon, Randy)
[1]: https://lore.kernel.org/linux-doc/20251008112409.33622-1-bagasdotme@gmail.com/
Documentation/admin-guide/sysrq.rst | 11 ++++-------
1 file changed, 4 insertions(+), 7 deletions(-)
diff --git a/Documentation/admin-guide/sysrq.rst b/Documentation/admin-guide/sysrq.rst
index 9c7aa817adc72d..6157d93e03a1e2 100644
--- a/Documentation/admin-guide/sysrq.rst
+++ b/Documentation/admin-guide/sysrq.rst
@@ -75,16 +75,13 @@ On other
submit a patch to be included in this section.
On all
- Write a single character to /proc/sysrq-trigger.
- Only the first character is processed, the rest of the string is
- ignored. However, it is not recommended to write any extra characters
- as the behavior is undefined and might change in the future versions.
- E.g.::
+ Write a single character to /proc/sysrq-trigger. E.g.::
echo t > /proc/sysrq-trigger
- Alternatively, write multiple characters prepended by underscore.
- This way, all characters will be processed. E.g.::
+ If a string (multiple characters) is written instead, only the
+ first character is processed unless the string is prepended by
+ an underscore, like::
echo _reisub > /proc/sysrq-trigger
base-commit: a1af37b935c73049c54cb1412cf0850212af420e
--
An old man doll... just what I always wanted! - Clara
next reply other threads:[~2025-10-16 10:36 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-16 10:36 Bagas Sanjaya [this message]
2025-10-17 4:25 ` [PATCH v2] Documentation: sysrq: Rewrite /proc/sysrq-trigger usage Randy Dunlap
2025-10-20 11:50 ` Tomáš Mudruňka
2025-10-20 19:12 ` Randy Dunlap
2025-10-21 8:37 ` Tomáš Mudruňka
2025-10-21 17:04 ` Randy Dunlap
2025-10-23 0:35 ` Bagas Sanjaya
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