Messages in this thread | | | From | Daniel Phillips <> | Subject | Re: The reason to call it 3.0 is the desktop (was Re: [OT] 2.6 not 3.0 - (NUMA)) | Date | Mon, 7 Oct 2002 21:21:28 +0200 |
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On Monday 07 October 2002 20:58, Chris Friesen wrote: > Andrew Morton wrote: > > > Go into ext2_new_inode, replace the call to find_group_dir with > > find_group_other. Then untar a kernel tree, unmount the fs, > > remount it and see how long it takes to do a > > > > `find . -type f xargs cat > /dev/null' > > > > on that tree. If your disk is like my disk, you will achieve > > full disk bandwidth. > > Pardon my ignorance, but what's the difference between find_group_dir > and find_group_other, and why aren't we using find_group_other already > if its so much faster?
These are the heuristics that determine where in the volume directory inodes are allocated:
http://lxr.linux.no/source/fs/ext2/ialloc.c#L221
Ext2 likes to spread directory inodes around the volume so that there is room to keep the associated file blocks nearby. This interacts rather poorly with readahead.
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