On Mon, 2007-09-17 at 12:29 -0700, Mingming Cao wrote: > On Fri, 2007-09-14 at 11:53 -0700, Mingming Cao wrote: > > jbd/jbd2: Replace slab allocations with page cache allocations > > > > From: Christoph Lameter <clameter@xxxxxxx> > > > > JBD should not pass slab pages down to the block layer. > > Use page allocator pages instead. This will also prepare > > JBD for the large blocksize patchset. > > > > Currently memory allocation for committed_data(and frozen_buffer) for > bufferhead is done through jbd slab management, as Christoph Hellwig > pointed out that this is broken as jbd should not pass slab pages down > to IO layer. and suggested to use get_free_pages() directly. > > The problem with this patch, as Andreas Dilger pointed today in ext4 > interlock call, for 1k,2k block size ext2/3/4, get_free_pages() waste > 1/3-1/2 page space. > > What was the originally intention to set up slabs for committed_data(and > frozen_buffer) in JBD? Why not using kmalloc? > > Mingming Looks good. Small suggestion is to get rid of all kmalloc() usages and consistently use jbd_kmalloc() or jbd2_kmalloc(). Thanks, Badari - 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
