Messages in this thread | | | Subject | Re: [patch] Converting writeback linked lists to a tree based data structure | From | Andi Kleen <> | Date | Fri, 18 Jan 2008 06:41:09 +0100 |
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Fengguang Wu <wfg@mail.ustc.edu.cn> writes: > > Suppose we want to grant longer expiration window for temp files, > adding a new list named s_dirty_tmpfile would be a handy solution.
How would the kernel know that a file is a tmp file?
> So the question is: should we need more than 3 QoS classes?
[just a random idea; i have not worked out all the implications]
Would it be possible to derive a writeback apriority from the ionice level of the process originating the IO? e.g. we have long standing problems that background jobs even when niced and can cause significant slow downs to foreground processes by starving IO and pushing out pages. ionice was supposed to help with that but in practice it does not seem to have helped too much and I suspect it needs more prioritization higher up the VM food chain. Adding such priorities to writeback would seem like a step in the right direction, although it would of course not solve the problem completely.
-Andi
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