[svn.haxx.se] · SVN Dev · SVN Users · SVN Org · TSVN Dev · TSVN Users · Subclipse Dev · Subclipse Users · this month's index

Re: fork/exec for hooks scripts with a large FSFS cache

From: Peter Samuelson <peter_at_p12n.org>
Date: Thu, 15 Nov 2012 09:28:59 -0600

[Philip Martin]
> If I configure a server with an FSFS cache that uses about 50% of
> available memory and then I use the server so the cache is in use I
> find that hook scripts fail to run because the fork/exec cannot
> allocate memory.

You didn't say what OS this is. It matters. Some are configured to
overcommit RAM allocation, because a lot of software tends to allocate
far more RAM than it actually needs. (fork() is only one case of

The other reason the OS matters is that some OSes support a vfork()
call which would avoid this issue entirely. Unfortunatley it seems
apr_proc_create() has no option to use vfork() instead of fork(), even
for OSes (Linux and most Unixes) that support it.

Received on 2012-11-15 16:29:43 CET

This is an archived mail posted to the Subversion Dev mailing list.