Messages in this thread | | | Date | Tue, 17 Aug 2010 10:41:40 +0800 | From | Wu Fengguang <> | Subject | Re: [RFC][PATCH] Per file dirty limit throttling |
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On Mon, Aug 16, 2010 at 12:19:50PM +0800, Nikanth Karthikesan wrote: > When the total dirty pages exceed vm_dirty_ratio, the dirtier is made to do > the writeback. But this dirtier may not be the one who took the system to this > state. Instead, if we can track the dirty count per-file, we could throttle > the dirtier of a file, when the file's dirty pages exceed a certain limit. > Even though this dirtier may not be the one who dirtied the other pages of > this file, it is fair to throttle this process, as it uses that file.
Nikanth, there's a more elegant solution in upstream kernel. See the comment for task_dirty_limit() in commit 1babe1838.
NFS may want to limit per-file dirty pages, to prevent long stall time inside the nfs_getattr()->filemap_write_and_wait() calls (and problems like that). Peter Staubach has similar ideas on it.
Thanks, Fengguang
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