From: Andrew Morton <akpm@linux-foundation.org>
To: Andi Kleen <andi@firstfloor.org>
Cc: linux-kernel@vger.kernel.org, eric.dumazet@gmail.com,
Andi Kleen <ak@linux.intel.com>
Subject: Re: [PATCH 2/4] posix-timers: limit the number of posix timers per process
Date: Tue, 30 Aug 2011 14:44:07 -0700 [thread overview]
Message-ID: <20110830144407.acdae071.akpm@linux-foundation.org> (raw)
In-Reply-To: <1314661157-22173-2-git-send-email-andi@firstfloor.org>
On Mon, 29 Aug 2011 16:39:15 -0700
Andi Kleen <andi@firstfloor.org> wrote:
> Now this is the main reason I wrote the whole patchkit: previously
> there was no limit on the maximum number of POSIX timers a process
> could allocate. This limits the amount of unswappable kernel memory
> a process can pin down this way.
>
> With the POSIX timer ids being per process we can do this limit
> per process now without allowing one process DoSing another.
>
> I implemented it as a sysctl, not a rlimit for now, because
> there was no clear use case for rlimit.
>
> The 1024 default is completely arbitrary, but seems reasonable
> for now.
Sorry, it should be an rlimit from day one, IMO.
Partly because rlimits are a better implementation.
Partly because if we later do it via rlimit, we're stuck having to
maintain the /proc knob for ever.
Partly because once rlimits are added, the /proc knob no longer has any
sane behaviour. Does it only modify /sbin/init? Does it do a global
process walk, modifying all threads?
next prev parent reply other threads:[~2011-08-30 21:44 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-29 23:39 [PATCH 1/4] posix-timers: move global timer id management to signal_struct v2 Andi Kleen
2011-08-29 23:39 ` [PATCH 2/4] posix-timers: limit the number of posix timers per process Andi Kleen
2011-08-30 21:44 ` Andrew Morton [this message]
2011-08-30 22:06 ` Andi Kleen
2011-08-30 22:22 ` Andrew Morton
2011-08-30 22:47 ` Andi Kleen
2011-08-30 23:02 ` Andrew Morton
2011-08-31 6:45 ` Jiri Slaby
2011-09-02 9:30 ` Thomas Gleixner
2011-08-29 23:39 ` [PATCH 3/4] posix-timers: Don't disable interrupts in idr_lock Andi Kleen
2011-08-29 23:39 ` [PATCH 4/4] posix-timers: turn it_signal into it_valid flag Andi Kleen
2011-09-02 10:06 ` Thomas Gleixner
2011-09-02 11:49 ` Eric Dumazet
2011-09-02 14:19 ` Thomas Gleixner
2011-09-04 16:56 ` Oleg Nesterov
2011-09-04 19:07 ` Andi Kleen
2011-09-04 20:29 ` Oleg Nesterov
2011-09-06 3:14 ` Andi Kleen
2011-09-06 14:51 ` Oleg Nesterov
2011-09-06 15:39 ` Eric Dumazet
2011-09-06 16:27 ` Oleg Nesterov
2011-09-06 18:47 ` Thomas Gleixner
2011-09-06 18:49 ` Oleg Nesterov
2011-09-06 19:16 ` Thomas Gleixner
2011-09-06 19:26 ` Oleg Nesterov
2011-09-06 19:45 ` Thomas Gleixner
2011-09-06 22:08 ` Oleg Nesterov
2011-09-06 22:34 ` Thomas Gleixner
2011-09-21 16:46 ` Thomas Gleixner
2011-09-21 17:56 ` Thomas Gleixner
2011-09-22 11:19 ` Thomas Gleixner
2011-09-06 19:30 ` Eric Dumazet
2011-09-06 20:10 ` Thomas Gleixner
2011-09-06 20:27 ` Eric Dumazet
2011-09-06 19:04 ` Eric Dumazet
2011-08-31 8:53 ` [PATCH 1/4] posix-timers: move global timer id management to signal_struct v2 Eric Dumazet
2011-08-31 16:57 ` Andi Kleen
2011-09-02 9:19 ` Thomas Gleixner
2011-09-02 10:05 ` Eric Dumazet
2011-09-19 21:46 ` Andi Kleen
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