Messages in this thread | ![/](/images/icornerl.gif) | | Subject | Re: [LKP] Re: [btrfs] e076ab2a2c: fio.write_iops -18.3% regression | From | Xing Zhengjun <> | Date | Wed, 13 Jan 2021 13:58:18 +0800 |
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On 1/12/2021 11:45 PM, David Sterba wrote: > On Tue, Jan 12, 2021 at 11:36:14PM +0800, kernel test robot wrote: >> Greeting, >> >> FYI, we noticed a -18.3% regression of fio.write_iops due to commit: >> >> >> commit: e076ab2a2ca70a0270232067cd49f76cd92efe64 ("btrfs: shrink delalloc pages instead of full inodes") >> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master >> >> >> in testcase: fio-basic >> on test machine: 192 threads Intel(R) Xeon(R) CPU @ 2.20GHz with 192G memory >> with following parameters: >> >> disk: 1SSD >> fs: btrfs >> runtime: 300s >> nr_task: 8 >> rw: randwrite >> bs: 4k >> ioengine: sync >> test_size: 256g > Though I do a similar test (emulating bit torrent workload), it's a bit > extreme as it's 4k synchronous on a huge file. It always takes a lot of > time but could point out some concurrency issues namely on faster > devices. There are 8 threads possibly competing for the same inode lock > or other locks related to it. > > The mentioned commit fixed another perf regression on a much more common > workload (untgrring files), so at this point drop in this fio workload > is inevitable.
Do you have a plan to fix it? Thanks. > _______________________________________________ > LKP mailing list -- lkp@lists.01.org > To unsubscribe send an email to lkp-leave@lists.01.org
-- Zhengjun Xing
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