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Date: Tue, 17 Feb 2009 08:31:04 +0100
From: Milan Broz <mbroz@redhat.com>
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Subject: Re: [linux-lvm] Re: Problems running my home-built LVM2
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Stefan Monnier wrote:
>>> _io in dev-io.c) would often return garbage (tho not always).  Not sure
>>> if it's a problem in LVM2, or in uClibc, or in the kernel, but I think
>>> I've already wasted more than enough time on this, so I'll just use
>>> the --disable-o_direct workaround.
>> We had a problem with O-direct several years ago which we blamed on a rogue
>> version of gcc.
> 
> Based on my experience I'd say that it seems to still be around.
> At least on `mipsel'.  I have since discovered that Debian's `lvm2'
> package disables O_DIRECT with the following lines:
> 
>    ifneq (,$(findstring $(DEB_HOST_ARCH), arm armeb hppa mips mipsel))
>    CONFIGURE_FLAGS += --disable-o_direct
>    endif

Ah, ok. That explains why my test on i686 arch & uClibc works:)

This really seems like problem unrelated to LVM2,
is possible that O_DIRECT is just buggy on ARM & similar archs
see http://lkml.org/lkml/2008/11/19/300 for example...

Milan 
--
mbroz@redhat.com