On Thu, Jun 08, 2006 at 03:26:40PM +0400, Vladimir V. Saveliev wrote: > > > It may go to the kernel as a 64MB write, but VFS sends it to the FS as > > > 64MB/4k separate 4k writes. > > > > Nonsense, > > Hans refers to generic_file_write which does > prepare_write > copy_from_user > commit_write > for each page.
That's not really the vfs but the generic pagecache routines. For some filesystems (e.g. XFS) only reservations for delayed allocations are performed in this path so it doesn't really matter. For not so advanced filesystems batching these calls would definitly be very helpful. Patches to get there are very welcome.
