Document new s6-svscan options

Signed-off-by: Laurent Bercot <ska@appnovation.com>

6 files changed, 28 insertions, 8 deletions

diff --git a/INSTALL b/INSTALL
index f73d32c..d7b48b7 100644
--- a/INSTALL
+++ b/INSTALL
@@ -7,7 +7,7 @@ Build Instructions
   - A POSIX-compliant C development environment
   - GNU make version 3.81 or later
   - skalibs version 2.13.2.0 or later: https://skarnet.org/software/skalibs/
-  - execline version 2.9.3.0 or later: https://skarnet.org/software/execline/
+  - execline version 2.9.4.0 or later: https://skarnet.org/software/execline/
       (You can disable this requirement at configure time, but will
       lose some functionality.)
   - Optional: nsss version 0.2.0.3 or later: https://skarnet.org/software/nsss/
diff --git a/NEWS b/NEWS
index 20acc4c..64c7804 100644
--- a/NEWS
+++ b/NEWS
@@ -5,6 +5,7 @@ In 2.11.4.0
 
  - New option to s6-svc: -s, to specify a signal by name (or number).
  - New option to s6-log: -t, to specify a timeout for partial last lines.
+ - s6-svscan rewrite: no more quadratic reaps, no more forced 1s wait on shutdown
 
 
 In 2.11.3.2
diff --git a/doc/index.html b/doc/index.html
index fe4cec7..e0b9a67 100644
--- a/doc/index.html
+++ b/doc/index.html
@@ -88,7 +88,7 @@ requirement if you link against the shared version of the skalibs
 library. </li>
  <li> (Optional, but really recommended for full functionality):
 <a href="//skarnet.org/software/execline/">execline</a> version
-2.9.3.0 or later. When s6 is built with execline support (which is the default),
+2.9.4.0 or later. When s6 is built with execline support (which is the default),
 execline is a build-time requirement, and also a run-time requirement for
 certain binaries that spawn scripts interpreted with
 <a href="//skarnet.org/software/execline/execlineb.html">execlineb</a>. </li>
diff --git a/doc/s6-svscan.html b/doc/s6-svscan.html
index 8b94cf4..ae815fc 100644
--- a/doc/s6-svscan.html
+++ b/doc/s6-svscan.html
@@ -27,7 +27,7 @@ the root or a branch of a <em>supervision tree</em>.
 <h2> Interface </h2>
 
 <pre>
-     s6-svscan [ -d <em>notif</em> ] [ -X <em>consoleholder</em> ] [ -c max ] [ -t <em>rescan</em> ] [ <em>scandir</em> ]
+     s6-svscan [ -d <em>notif</em> ] [ -X <em>consoleholder</em> ] [ -c max | -C services_max ] [ -L name_max ] [ -t <em>rescan</em> ] [ <em>scandir</em> ]
 </pre>
 
 <ul>
@@ -67,6 +67,7 @@ even that the relevant <a href="s6-supervise.html">s6-supervise</a> processes ha
 been started. If you need to test for <em>deep readiness</em>, meaning that all the
 services in the supervision tree have been started and are ready, you cannot rely
 on this option. </li>
+
  <li> <tt>-X&nbsp;<em>consoleholder</em></tt>&nbsp;: assume the output console is available
 on descriptor <em>consoleholder</em>. If this option is given, and a <tt>s6-svscan-log</tt>
 service exists, the <a href="s6-supervise.html">s6-supervise</a> process for that service
@@ -75,17 +76,31 @@ for a setup done via <a href="//skarnet.org/software/s6-linux-init/">s6-linux-in
 where all error messages go to the <tt>s6-svscan-log</tt> catch-all logger service by
 default, except messages from this service itself, which fall back to <em>consoleholder</em>.
 If you're not sure what to use this option for, or how, you don't need it. </li>
- <li> <tt>-c&nbsp;<em>max</em></tt>&nbsp;: maintain services for up to <em>max</em>
-service directories. Default is 500. Lower limit is 2. Upper limit is 90000. If
+
+ <li> <tt>-C&nbsp;<em>services_max</em></tt>&nbsp;: maintain services for up to <em>services_max</em>
+service directories, including loggers. Default is 1000. Lower limit is 4. Upper limit is 160000. If
 you're increasing this value from the default, please note that:
  <ul>
   <li> The higher <em>max</em> is, the more stack memory s6-svscan will use,
-up to 100 bytes per service. </li>
+up to 200 bytes per service, also depending on the value of <em>name_max</em>. </li>
   <li> s6-svscan uses 2 file descriptors per logged service. </li>
  </ul>
  It is the admin's responsibility to make sure that s6-svscan has enough available
 descriptors to function properly and does not exceed its stack limit. The default
-of 500 is safe and provides enough room for every reasonable system. </li>
+of 1000 is safe and provides enough room for every reasonable system. </li>
+
+ <li> <tt>-c&nbsp;<em>max</em></tt>&nbsp;: a deprecated way of setting <em>services_max</em>.
+If the <tt>-c</tt> option is given, the value of <em>max</em> is doubled, and the result
+is used as <em>services_max</em>. The reason for the change is that previous versions
+of s6-svscan handled services+loggers as a single entity; but this version of s6-svscan
+handles services and loggers in the same way, so with the default values it's now possible
+to handle e.g. 600 unlogged services, whereas previously you were limited to 500 because
+s6-svscan was reserving room for the loggers. </li>
+
+ <li> <tt>-L&nbsp;<em>name_max</em></tt>&nbsp;: the maximum length of a name in the
+scan directory. Names longer than <em>name_max</em> won't be taken into account.
+Default is 251. It cannot be set lower than 11 or higher than 1019. </li>
+
  <li> <tt>-t&nbsp;<em>rescan</em></tt>&nbsp;: perform a scan every <em>rescan</em>
 milliseconds. If <em>rescan</em> is 0 (the default), automatic scans are never performed after
 the first one and s6-svscan will only detect new services when told to via a
diff --git a/doc/upgrade.html b/doc/upgrade.html
index 2922250..4dea3df 100644
--- a/doc/upgrade.html
+++ b/doc/upgrade.html
@@ -23,8 +23,12 @@
 <ul>
  <li> <a href="//skarnet.org/software/skalibs/">skalibs</a>
 dependency bumped to 2.13.2.0. </li>
+ <li> <a href="//skarnet.org/software/execline/">execline</a>
+dependency bumped to 2.9.4.0. </li>
  <li> New <tt>-s</tt> option to <a href="s6-svc.html">s6-svc</a>. </li>
  <li> New <tt>-t</tt> option to <a href="s6-log.html">s6-log</a>. </li>
+ <li> <a href="s6-svscan.html">s6-svscan</a> rewrite; new options
+<tt>-C</tt> and <tt>-L</tt>. </li>
 </ul>
 
 <h2> in 2.11.3.2 </h2>
diff --git a/src/supervision/s6-svscan.c b/src/supervision/s6-svscan.c
index e687e29..32655cc 100644
--- a/src/supervision/s6-svscan.c
+++ b/src/supervision/s6-svscan.c
@@ -775,7 +775,7 @@ int main (int argc, char const *const *argv)
           if (!tain_future(&scan_deadline)) flag |= 1 ;
           if (!tain_future(&start_deadline)) flag |= 2 ;
         }
-        LOLDEBUG("loop: %d ms%s%s", ms, flag & 1 ? ", scan" : "", flag & 2 ? ", start" : "") ;
+        LOLDEBUG("loop: %d ms", ms) ;
       }
 #endif
       r = iopause_g(x, 2, &deadline) ;