Re: Hang on large copy_from_user with PREEMPT_NONE

[Dave Jones]

On Tue, Apr 07, 2015 at 11:12:31AM -0700, Linus Torvalds wrote:
 > On Apr 7, 2015 10:58 AM, "Dave Jones" <davej@xxxxxxxxxxxxxxxxx> wrote:
 > >  >
 > >  > +#define COPY_CHUNK_SIZE (16*PAGE_SIZE)
 > >
 > > This needs to be bigger, just to accomodate things like xfs, which
 > > on my system is over 1mb.  I think some out-of-tree modules
 > > (not that I care deeply) are even bigger.
 > 
 > Umm. It will happily copy megabytes of data. Or gigabytes. It just doors it
 > in smaller chunks, and make sure to test the return value and possibly
 > reschedule in between.

brain no worky. You are of course, correct.

	Dave
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