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Date: Thu, 4 Nov 2010 15:45:43 +0000
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Gregory Giguashvili <Gregory.Giguashvili@PDGM.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: Change signal mask after vfork/clone system call
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On Thu, 4 Nov 2010 15:37:05 +0000
Gregory Giguashvili <Gregory.Giguashvili@PDGM.com> wrote:

> > Fork on pretty much any Unix like system around today does copy-on-write
> >so while not as efficient as vfork should be fine for most purposes.
> Yes, but the problem is that fork simply does not work when a process has huge resident size and vm.overcommit_memory=0 as preferred by Linux distributions we run on. So, processes with large RSS footprint may occasionally fail fork, even if a tiny process is to be started.
> 
> Using vfork always works, but has the signal mask problem. Catch 22?

And is there a reason you can't mask the signals, vfork and unmask them
again after the parent continues ?