linux-kernel - Re: [PATCH 1/3] epoll: increase default max_user

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 28 Jan 2009 08:52:51 -0800 (PST)
From:	Davide Libenzi <davidel@...ilserver.org>
To:	Vegard Nossum <vegard.nossum@...il.com>
cc:	Bron Gondwana <brong@...tmail.fm>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Greg KH <gregkh@...e.de>
Subject: Re: [PATCH 1/3] epoll: increase default max_user_instances to 1024

On Wed, 28 Jan 2009, Vegard Nossum wrote:

> On Wed, Jan 28, 2009 at 6:32 AM, Bron Gondwana <brong@...tmail.fm> wrote:
> > That's clearly not happening here - so it seems that maybe our "happy
> > medium" is actually in closer inspection of what's going on rather than
> > a blanket low N to keep N^2 down.
> 
> Mh, could another solution to this all be to limit the number times
> you can add a single epoll descriptor to another descriptor's set?

In the example that was posted, a single fd was added a single time inside 
the other 1000+ fds. Epoll already has detection for too long chains and 
closed loops, but you can't put those in the fast path. And epoll_ctl() is 
one of those.


- Davide


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