Messages in this thread | | | Date | Tue, 11 Nov 2008 13:22:11 -0500 | From | Christoph Hellwig <> | Subject | Re: Queue upcall locking (was: [dm-devel] [RFC][PATCH] fix dm_any_congested() to properly sync up with suspend code path) |
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On Mon, Nov 10, 2008 at 09:40:18AM -0500, Mikulas Patocka wrote: > > - If the device is suspended, the response should be that it is > > congested, I'd have thought. > > Yes, but these congestion upcalls are used only for optimization and the > device is suspended for so small time, that it doesn't matter if we > optimize io acces in small moment or not.
We use device congested to not block pdflush on a device that can't currently accept I/O. For a suspended device congested is always correct, pdflush will just come back a little later and in the mean time write out stuff that doesn't delay it.
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