Re: [Qemu-devel] [PATCH v2 2/2] block/raw-posix: use seek_hole ahead of fiemap

2014-09-26 Thread Eric Blake
On 09/25/2014 05:14 PM, Tony Breeds wrote: > try_fiemap() uses FIEMAP_FLAG_SYNC which has a significant performance > impact. > > Prefer seek_hole() over fiemap() to avoid this impact where possible. > seek_hole is more widely used and, arguably, has potential to be > optimised in the kernel. It

Re: [Qemu-devel] [PATCH v2 2/2] block/raw-posix: use seek_hole ahead of fiemap

2014-09-26 Thread Max Reitz
On 26.09.2014 01:14, Tony Breeds wrote: try_fiemap() uses FIEMAP_FLAG_SYNC which has a significant performance impact. Prefer seek_hole() over fiemap() to avoid this impact where possible. seek_hole is more widely used and, arguably, has potential to be optimised in the kernel. Reported-By: Mic

[Qemu-devel] [PATCH v2 2/2] block/raw-posix: use seek_hole ahead of fiemap

2014-09-25 Thread Tony Breeds
try_fiemap() uses FIEMAP_FLAG_SYNC which has a significant performance impact. Prefer seek_hole() over fiemap() to avoid this impact where possible. seek_hole is more widely used and, arguably, has potential to be optimised in the kernel. Reported-By: Michael Steffens Signed-off-by: Tony Breeds