On Fri, 20 Apr 2012, Bernd Schubert wrote: > On 04/19/2012 09:20 PM, Theodore Ts'o wrote: > > As I had brought up during one of the lightning talks at the Linux > > Storage and Filesystem workshop, I am interested in introducing two new > > open flags, O_HOT and O_COLD. These flags are passed down to the > > individual file system's inode operations' create function, and the file > > system can use these flags as a hint regarding whether the file is > > likely to be accessed frequently or not. > > > > In the future I plan to do further work on how ext4 would use these > > flags, but I want to first get the ability to pass these flags plumbed > > into the VFS layer and the code points for O_HOT and O_COLD reserved. > > > > Ted, you still remember the directory-block read-ahead patches I sent last > year for ext4 and which you declined, as it would add another mount parameter > for ext4? > > http://www.digipedia.pl/usenet/thread/11916/24502/#post24502 > > > If an application could use those flags to the file system (and then not only > ext4, but any file system) to indicate a certain directory is important and > frequently accessed, it would be simple to update those patches to work > without another mount option. > And while I updating our FhGFS meta data on disk layout to workaround the > general problem we, we (and for example Lustre) are still affected the > object-storage-side. > > > Thanks, > Bernd Nice, there are probably lots of flags we can think of, so we definitely need good interface for it as we certainly do not want to use O_HOT open flags here :) Thanks! -Lukas -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
