On Tue, Nov 30, 2010 at 10:35:11AM +0100, Samuel Thibault wrote: > Mike Hommey, le Tue 30 Nov 2010 10:07:55 +0100, a écrit : > > On Mon, Nov 29, 2010 at 07:18:17AM +0100, Guillem Jover wrote: > > > > What's going on here? sync_file_range() is a Linux specific system > > > > call that has been around for a while. It allows program to control > > > > when writeback happens in a very low-level fashion. The first set of > > > > sync_file_range() system calls causes the system to start writing back > > > > each file once it has finished being extracted. It doesn't actually > > > > wait for the write to finish; it just starts the writeback. > > > > > > Hmm, ok so what about posix_fadvise(fd, 0, 0, POSIX_FADV_DONTNEED) > > > instead, skimming over the kernel source seems to indicate it might > > > end up doing more or less the same thing but in a portable way? > > > > On the other hand, there is no guarantee that other kernels do the same, > > Err, that's posix.
Being posix doesn't guarantee that posix_fadvise(fd, 0, 0, POSIX_FADV_DONTNEED) is going to start write back, which is the desired effect, but not what you may actually get, depending on the kernel. Mike -- To UNSUBSCRIBE, email to debian-boot-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20101130103043.ga9...@glandium.org
