Messages in this thread | | | Date | Thu, 18 Apr 1996 13:19:28 -0700 | From | "Leonard N. Zubkoff" <> | Subject | Re: 1.2.13 v 1.3.81 open() speed results |
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Date: Tue, 16 Apr 1996 15:48:02 +0100 (BST) From: Dirk-Jan Koopman <djk@chbi.co.uk>
On Tue, 16 Apr 1996, Leonard N. Zubkoff wrote:
> If someone would kindly point me at the kernel profiling app, I will > recompile and profile the kernel. > > Don't bother. I'm 99.99% certain you'll find that get_empty_inode is the > loser. I've already reported this and run some profiles for Linus... >
Good, I had a cursory look at the fileopen code; is there any profit on the old idea of a 'half open' chain. This was a George 3 idea which effectively hid 'closed' files on double headed chain of finite length. This provided a secondary cache of highly reusable files such directories.
The idea of course is to search the 'half open' chain for a filename first.
1.3.91 now includes a fix from Linus for the performance degradation I encountered. You might want to re-run your test now and see if the problem is still present. 1.3.91 now beats 1.2.13 for me on the test I was running.
Leonard
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