Re: CVS commit: src/bin/cp

[David Holland <dholland-sourcechanges%netbsd.org@localhost>]

On Fri, Oct 22, 2010 at 05:56:06PM +0000, Antti Kantee wrote:
 > Disable mmap path.  With the current vnode locking scheme it has
 > a very annoying property: if the source media is slow (like a slow
 > network), the target file will be locked for the duration of the
 > entire max 8MB write and cause processes attempting to e.g. stat()
 > it to "tstile" (for several minutes in the worst case).  Revisit
 > this if/when vnode locking gets a little smarter.

Wouldn't it be better to just ratchet back the block size to something
like 64K that happens faster?

 > chs ok (although he would rather see vnode locking improvements,
 > but that's a slightly larger project)

Because individual write() calls are supposed to be atomic, I don't
think there is such a thing as a locking improvement that'll help with
this behavior. :-/

Except I guess going to some kind of multiversion model for vnodes.

-- 
David A. Holland
dholland%netbsd.org@localhost