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From: Oleg Drokin <green@linuxhacker.ru>
To: BlaisorBlade <blaisorblade_spam@yahoo.it>
Cc: jdike@karaya.com, user-mode-linux-devel@lists.sourceforge.net
Subject: Re: [uml-devel] Re: [PATCH] Fix for annoying problem with hostfs readdir problems.
Date: Mon, 19 Apr 2004 01:26:20 +0300	[thread overview]
Message-ID: <20040418222620.GA1779@linuxhacker.ru> (raw)
In-Reply-To: <200404181726.23698.blaisorblade_spam@yahoo.it>

Hello!

On Sun, Apr 18, 2004 at 05:26:23PM +0200, BlaisorBlade wrote:
> > >    So the annoying problem with readdir not working on hostfs (on 2.6
> > > host kernel only for me) was finally hunted to memory allocation
> > >    problem during opendir.
> I've experienced it too onto 2.6 and someone else had the same problem - but 
> that patch is not perfect. Using always vmalloc() instead of kmalloc() is 
> wrong - vmalloc is slower, and Linus spoke against vmalloc(); it would also 
> slow down everything using malloc().

Well, speed is not of much an issue there, that function is only used for
glibc allocations. And that read_dir() is probably the only place that
causes glibc to allocate something.

> Probably you should use vmalloc() only if size is > the size limit (if this is 
> the problem, as I guess). When you come at free() it is a bit hard, but IIRC 
> vmalloc() can return pointers inside a certain, known memory area, right? So 
> it is possible to understand what function to call.

I am sure that all of the complexity you propose to implement won't pay off in
the end.

Bye,
    Oleg


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      reply	other threads:[~2004-04-18 22:27 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-04-15 21:03 [uml-devel] [PATCH] Fix for annoying problem with hostfs readdir problems Oleg Drokin
2004-04-15 21:46 ` [uml-devel] " Oleg Drokin
2004-04-18 15:26   ` BlaisorBlade
2004-04-18 22:26     ` Oleg Drokin [this message]

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