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-rw-r--r--Documentation/sysctl/kernel.txt22
1 files changed, 22 insertions, 0 deletions
diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt
index b3d8b4922740..a028b92001ed 100644
--- a/Documentation/sysctl/kernel.txt
+++ b/Documentation/sysctl/kernel.txt
@@ -22,6 +22,7 @@ show up in /proc/sys/kernel:
22- callhome [ S390 only ] 22- callhome [ S390 only ]
23- auto_msgmni 23- auto_msgmni
24- core_pattern 24- core_pattern
25- core_pipe_limit
25- core_uses_pid 26- core_uses_pid
26- ctrl-alt-del 27- ctrl-alt-del
27- dentry-state 28- dentry-state
@@ -135,6 +136,27 @@ core_pattern is used to specify a core dumpfile pattern name.
135 136
136============================================================== 137==============================================================
137 138
139core_pipe_limit:
140
141This sysctl is only applicable when core_pattern is configured to pipe core
142files to user space helper a (when the first character of core_pattern is a '|',
143see above). When collecting cores via a pipe to an application, it is
144occasionally usefull for the collecting application to gather data about the
145crashing process from its /proc/pid directory. In order to do this safely, the
146kernel must wait for the collecting process to exit, so as not to remove the
147crashing processes proc files prematurely. This in turn creates the possibility
148that a misbehaving userspace collecting process can block the reaping of a
149crashed process simply by never exiting. This sysctl defends against that. It
150defines how many concurrent crashing processes may be piped to user space
151applications in parallel. If this value is exceeded, then those crashing
152processes above that value are noted via the kernel log and their cores are
153skipped. 0 is a special value, indicating that unlimited processes may be
154captured in parallel, but that no waiting will take place (i.e. the collecting
155process is not guaranteed access to /proc/<crahing pid>/). This value defaults
156to 0.
157
158==============================================================
159
138core_uses_pid: 160core_uses_pid:
139 161
140The default coredump filename is "core". By setting 162The default coredump filename is "core". By setting