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* [PATCH v4 2/4] man/man5/tunables.conf: Document system-wide tunables config
@ 2026-08-03 19:21 DJ Delorie
  2026-08-06 14:37 ` Alejandro Colomar
  0 siblings, 1 reply; 41+ messages in thread
From: DJ Delorie @ 2026-08-03 19:21 UTC (permalink / raw)
  To: Alejandro Colomar; +Cc: linux-man


Signed-off-by: DJ Delorie <dj@redhat.com>

---
 man/man5/tunables.conf.5 | 132 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 132 insertions(+)
 create mode 100644 man/man5/tunables.conf.5

diff --git a/man/man5/tunables.conf.5 b/man/man5/tunables.conf.5
new file mode 100644
index 000000000..44b32d40c
--- /dev/null
+++ b/man/man5/tunables.conf.5
@@ -0,0 +1,132 @@
+.TH tunables.conf 5 (date) "Linux man-pages (unreleased)"
+.SH NAME
+tunables.conf \- tunables configuration file
+.SH SYNOPSIS
+.nf
+.B /etc/tunables.conf
+.fi
+.SH DESCRIPTION
+Tunables are a feature in the GNU C Library
+that allows application authors and distribution maintainers
+to alter the runtime library behavior to match their workload.
+For a list of supported tunables,
+please consult the glibc manual
+that corresponds to your installed version of glibc,
+or run the following command:
+.P
+.in +4n
+.EX
+ld.so \-\-list\-tunables
+.EE
+.P
+The file is parsed by
+.BR \%ldconfig (8)
+and the results stored in
+.IR /etc/ld.so.cache .
+The resulting data is read when a new process is created by
+.IR ld.so .
+.P
+Each line in the file
+.I /etc/tunables.conf
+specifies a tunable,
+which is specified with a string of the form
+.IB name = value \f[R].\f[]
+.P
+The syntax allows lines to start with the keyword
+.I include
+followed by a
+.BR \%glob (7)
+pattern.
+Files matching that pattern will be processed
+as if their contents were included at that point.
+.P
+Each line may include zero or more keywords or symbols at the beginning,
+which affect how each tunable affects each processes.
+The keywords must be separated by whitespace,
+but the symbols need not be.
+.TP
+.B overridable
+.TQ
+.B +
+Allow the tunable to be overridden by the
+.B GLIBC_TUNABLES
+environment variable when the process runs
+(this is the default).
+.TP
+.B nonoverridable
+.TQ
+.B \-
+Do not allow the tunable to be overridden by the environment variable.
+.TP
+.B onlysecure
+.TQ
+.B @
+The tunable applies only to
+.B AT_SECURE
+processes,
+such as one started from a set-user-ID program,
+or one with elevated capabilities.
+.TP
+.B nonsecure
+.TQ
+.B $
+The tunable applies only to
+.RB non- AT_SECURE
+processes (this is the default).
+.TP
+.B anysecure
+.TQ
+.B *
+The tunable applies to both
+.B AT_SECURE
+and
+.RB non- AT_SECURE
+processes.
+.P
+The file may also contain
+.IR filters ,
+which limit the tunables following it,
+up to the end of the file
+(or end of the included file,
+or start of a new included file)
+or a line with only
+.B []
+on it.
+The syntax is:
+.P
+.in +4n
+.EX
+.RI [ filter : pattern ]
+.EE
+.in
+.TP
+.B proc
+The
+.B proc
+filter limits the following tunables to processes
+whose name matches the pattern.
+The pattern may be an absolute path
+or just the base name.
+.SH FILES
+.TP
+.I /etc/tunables.conf
+.TP
+.I /etc/ld.so.cache
+cached copy of tunables
+.SH EXAMPLES
+Example configuration file:
+.P
+.in +4n
+.EX
+glibc.malloc.arenas_max=5
+onlysecure glibc.malloc.arenas_max=1
+\-glibc.pthread.rseq=1
+[proc:/bin/bad.program]
+\-glibc.pthread.rseq=0
+[proc:some.program]
+\-glibc.malloc.mmap_threshold=65536
+.EE
+.in
+.SH SEE ALSO
+.BR ld.so (8),
+.BR ldconfig (8)
-- 
2.47.3


^ permalink raw reply related	[flat|nested] 41+ messages in thread

end of thread, other threads:[~2026-08-30 13:17 UTC | newest]

Thread overview: 41+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-08-03 19:21 [PATCH v4 2/4] man/man5/tunables.conf: Document system-wide tunables config DJ Delorie
2026-08-06 14:37 ` Alejandro Colomar
2026-08-06 15:33   ` DJ Delorie
2026-08-06 19:14     ` Alejandro Colomar
2026-08-06 20:17       ` DJ Delorie
2026-08-06 20:31         ` Alejandro Colomar
2026-08-06 20:42           ` DJ Delorie
2026-08-07  2:12             ` G. Branden Robinson
2026-08-07  3:29               ` DJ Delorie
2026-08-07  3:49                 ` G. Branden Robinson
2026-08-07  4:01                   ` DJ Delorie
2026-08-07  4:09                     ` G. Branden Robinson
2026-08-23 12:29               ` Using LS/LE (was: [PATCH v4 2/4] man/man5/tunables.conf: Document system-wide tunables config) Alejandro Colomar
2026-08-23 13:27                 ` G. Branden Robinson
2026-08-23 13:55                   ` Alejandro Colomar
2026-08-23 14:16                     ` G. Branden Robinson
2026-08-23 15:06                       ` Alejandro Colomar
2026-08-23 16:44                         ` G. Branden Robinson
2026-08-23 19:30                           ` Alejandro Colomar
2026-08-23 20:40                             ` G. Branden Robinson
2026-08-23 23:11                               ` Alejandro Colomar
2026-08-24  1:11                                 ` G. Branden Robinson
2026-08-24  2:01                                   ` Using LS/LE Collin Funk
2026-08-24 11:08                                     ` Alejandro Colomar
2026-08-24 11:00                                   ` Using LS/LE (was: [PATCH v4 2/4] man/man5/tunables.conf: Document system-wide tunables config) Alejandro Colomar
2026-08-23 22:31                             ` autotools, was: Using LS/LE Ingo Schwarze
2026-08-24  0:09                               ` Alejandro Colomar
2026-08-29  4:36                               ` G. Branden Robinson
2026-08-29 11:34                                 ` Ingo Schwarze
2026-08-29 12:51                                   ` Alejandro Colomar
2026-08-29 19:16                                     ` G. Branden Robinson
2026-08-29 21:43                                       ` Alejandro Colomar
     [not found]                             ` <8DE76435-CBDB-42D6-9E0F-9E27291560B6@icloud.com>
2026-08-29  8:42                               ` Using LS/LE (was: [PATCH v4 2/4] man/man5/tunables.conf: Document system-wide tunables config) Alejandro Colomar
2026-08-29  8:45                                 ` Alejandro Colomar
2026-08-29  8:52                                   ` Alejandro Colomar
2026-08-29  9:02                                     ` Alejandro Colomar
2026-08-29  9:39                               ` Ingo Schwarze
2026-08-29 13:10                                 ` configure separate from make or not (was: Using LS/LE) Alejandro Colomar
2026-08-29 15:31                                   ` configure separate from make or not Ingo Schwarze
2026-08-29 20:49                                     ` Alejandro Colomar
2026-08-30 13:17                                       ` Alejandro Colomar

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