Messages in this thread | | | Date | Wed, 12 Sep 2012 07:25:37 +0800 | From | Fengguang Wu <> | Subject | Re: [PATCH 1/2] writeback: add dirty_background_time per bdi variable |
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On Wed, Sep 12, 2012 at 08:12:40AM +0900, Namjae Jeon wrote: > >> > >> To be frank, no realistic NFS servers will use USB disk as backing > >> storage. So that rational for reducing "initial" delays is weak. > >> Continuous write performance to HDD is much more important. Do you > >> have numbers for that? > > > > Actually, we use USB HDD and USB Flash devices at NFS server. > > There can be other similar users as well. So it might be useful to > > provide this tuning feature other. > > As default value is zero, it is disabled by default and it should not > > impact normal writeback. > > > > I will share large file writes test result on NFS client on USB HDD > > with/without tuning with patch. > Hi. Wu. > I share 1GB continous write test result. > > -> create a 1000 MB file > For continuous write - create 1 GB file > > RecSize WriteSpeed > 10485760 10.47MB/sec > 1048576 10.35MB/sec > 524288 10.48MB/sec > 262144 10.48MB/sec > 131072 10.52MB/sec > 65536 10.56MB/sec > 32768 10.64MB/sec > 16384 10.31MB/sec > 8192 10.52MB/sec > 4096 10.45MB/sec > > I will update changelog in patch.
Thanks! What's the server side setting and can you give a comparison of different background writeback thresholds? This is this patch's target use cases, after all.
Thanks, Fengguang
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