Bug 32382

Summary:	Raise default hard ulimit on number of files to 4096 or so
Product:	Networking	Reporter:	Dan Kegel (dank)
Component:	Other	Assignee:	Arnaldo Carvalho de Melo (acme)
Status:	CLOSED OBSOLETE
Severity:	normal	CC:	akpm, alan
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:		Subsystem:
Regression:	No	Bisected commit-id:
Attachments:	Raise default hard ulimit on number of files to 4096

Description Dan Kegel 2011-03-31 20:12:14 UTC

Apps are increasingly using more than 1024 file descriptors.
See discussion in several distro bug trackers, e.g.
https://bugs.launchpad.net/bugs/663090
https://issues.rpath.com/browse/RPL-2054

You don't want to raise the default soft limit, since that might break
apps that use select(), but it's safe to raise the default hard limit;
that way, apps that know they need lots of file descriptors can raise their
soft limit without needing root, and without user intervention.

Ubuntu is doing this for 11.04 by changing include/asm-generic/resource.h:

-	[RLIMIT_NOFILE]		= {       INR_OPEN,       INR_OPEN },	\
+	[RLIMIT_NOFILE]		= {       INR_OPEN,     INR_OPEN*4 },	\

They chose to do this with a kernel change because they have a policy
of not changing kernel defaults in userland.

While 4096 might not be enough for *all* apps, it seems to be plenty
for the apps I've seen lately that are unhappy with 1024.

Comment 1 Andrew Morton 2011-03-31 20:24:33 UTC

Send it to lkml, please.  CC me and anyone else who might be interested.

Comment 2 Tim Gardner 2011-03-31 21:28:21 UTC

Created attachment 52812 [details]
Raise default hard ulimit on number of files to 4096

Submitted on lkml