On Fri, Oct 30, 2026 at 02:06:11AM +0100, Denis V. Lunev wrote: > From: Denis V. Lunev <[email protected]> > > Getting or putting nothing cannot change the pool, yet both calls take > the mutex, and co_put_to_shres() also wakes every waiter to find the > pool unchanged. Return early when n is zero. > > block-copy is about to reserve nothing for write-zeroes tasks the target > serves without a buffer, which makes such calls the common case for a > mostly-zero image. > > Suggested-by: Vladimir Sementsov-Ogievskiy <[email protected]> > Signed-off-by: Denis V. Lunev <[email protected]> > CC: Vladimir Sementsov-Ogievskiy <[email protected]> > CC: John Snow <[email protected]> > CC: Andrey Drobyshev <[email protected]> > --- > util/qemu-co-shared-resource.c | 8 ++++++++ > 1 file changed, 8 insertions(+)
Reviewed-by: Eric Blake <[email protected]> -- Eric Blake, Principal Software Engineer Red Hat, Inc. Virtualization: qemu.org | libguestfs.org
