Messages in this thread | | | Date | Wed, 13 Mar 2002 13:51:18 -0800 | From | Mike Fedyk <> | Subject | Re: [CFT] delayed allocation and multipage I/O patches for 2.5.6. |
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On Wed, Mar 13, 2002 at 11:50:32AM -0800, Andrew Morton wrote: > Now, I think it's fair to say that the ext2/ext3 inter-file fragmentation > issue is one of the three biggest performance problems in Linux. (The > other two being excessive latency in the page allocator due to VM writeback > and read latency in the I/O scheduler). > > The fix for interfile fragmentation lies inside ext2/ext3, not inside > any generic layers of the kernel. And this really is a must-fix, > because the completion time for writeback is approximately proportional > to the size of the filesystem. So we're getting, what? Fifty percent > slower per year? > > The `tar xfz linux.tar.gz ; sync' workload can be sped up 4x-5x by > using find_group_other() for directories. I spent a week or so > poking at this when it first came up. Basically, *everything* > which I did to address the rapid-growth problem ended up penalising > the slow-growth fragmentation - long-term intra-file fragmentation > suffered at the expense of short-term inter-file fragmentation.
I know ReiserFS has similar problems.
Can anyone say wheather JFS or XFS has this problem also? - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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