lkml.org 
[lkml]   [1999]   [May]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: /dev/poll vs. aio_ (was: Re: Proposal: Get rid of most accept mutex)calls on hybrid server.)
Stephen C. Tweedie writes:
> Hi,
>
> On Sat, 29 May 1999 07:51:25 +1000, Richard Gooch <rgooch@atnf.csiro.au> said:
>
> > Why not just increase the RT signal queue size? Add a command to
> > prctl(2) so the application can tune this.
>
> Letting the application increase the queue size opens up a DOS attack:
> you can lock down arbitrarily much non-swappable memory with it. root
> can already tune it via /proc/sys/kernel/rtsig-max.

OK, so there's a way for the administrator to tune this. I note the
default on my system is 1024, which should be fine for most
applications. However, for a busy WWW server, how deep should the
queue be? Anyone got a benchmark?

Assuming you need a much deeper queue (4096 for example), then tuning
rtsig-max will work, but at the cost of increasing the queue depth for
all processes, most of which won't need it. So how about creating
rtsig-limit and adding a command to prctl(2), so that a process which
needs to increase the queue depth can do so (up to the sysadmin tuned
limit), but other processes use the default?

Regards,

Richard....

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:51    [W:0.226 / U:0.176 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site