On Aug 21, 2008 20:48 +0530, Aneesh Kumar wrote: > On Wed, Aug 20, 2008 at 02:55:25PM -0700, Mingming Cao wrote: > > I have a feeling that we did not try very hard before invalidate the > > dirty page which fail to map to disks. Perhaps we should try a few more > > times before give up. Also in that case, perhaps we should turn off > > delalloc fs wide, so the new writers won't take the subsequently made > > avaible free blocks away from this unlucky delalloc da writepages. > > How do we try hard ? The mballoc already try had to allocate blocks. So I > am not sure what do we achieve by requesting for block allocation again. One reason is that if blocks are being released then they cannot be reallocated until the transaction has committed. Running something like iozone in a loop on a filesystem that has only as much free space as the size of the output file can run out of space after a few loops because of this, so definitely retrying the allocation can help. Also, keeping the pages in RAM may allow them to be written again if the user detects the ENOSPC and deletes some files... Cheers, Andreas -- Andreas Dilger Sr. Staff Engineer, Lustre Group Sun Microsystems of Canada, Inc. -- 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
