Re: xfsdump stuck in io_schedule

[Andrew Morton <akpm@xxxxxxxxx>]

Zlatko Calusic wrote:
> 
> Oh, yes, you're completely right, of course. It's the pinned part of
> page cache that makes big pressure on the memory. Whole lot of
> inactive page cache pages (~700MB in my case) is not really good
> indicator of recyclable memory, when (probably) a big part of it is
> pinned and can't be thrown out. So it is VM, after all.

Does xfs_dump actually pin 700 megs of memory??

If someone could provide a detailed description of what xfs_dump
is actually doing internally, that may help me shed some light.
xfs_dump is actually using kernel support for coherency reasons,
is that not so?   How does it work?

Does the machine have highmem?

What was the backtrace into the page allocation failure?