Messages in this thread | | | Subject | Re: [PATCH -next 00/11] support concurrent sync io for bfq on a specail occasion | From | "yukuai (C)" <> | Date | Thu, 17 Mar 2022 09:49:16 +0800 |
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friendly ping ...
在 2022/03/11 14:31, yukuai (C) 写道: > friendly ping ... > > 在 2022/03/05 17:11, Yu Kuai 写道: >> Currently, bfq can't handle sync io concurrently as long as they >> are not issued from root group. This is because >> 'bfqd->num_groups_with_pending_reqs > 0' is always true in >> bfq_asymmetric_scenario(). >> >> This patchset tries to support concurrent sync io if all the sync ios >> are issued from the same cgroup: >> >> 1) Count root_group into 'num_groups_with_pending_reqs', patch 1-5; >> >> 2) Don't idle if 'num_groups_with_pending_reqs' is 1, patch 6; >> >> 3) Don't count the group if the group doesn't have pending requests, >> while it's child groups may have pending requests, patch 7; >> >> This is because, for example: >> if sync ios are issued from cgroup /root/c1/c2, root, c1 and c2 >> will all be counted into 'num_groups_with_pending_reqs', >> which makes it impossible to handle sync ios concurrently. >> >> 4) Decrease 'num_groups_with_pending_reqs' when the last queue completes >> all the requests, while child groups may still have pending >> requests, patch 8-10; >> >> This is because, for example: >> t1 issue sync io on root group, t2 and t3 issue sync io on the same >> child group. num_groups_with_pending_reqs is 2 now. >> After t1 stopped, num_groups_with_pending_reqs is still 2. sync io from >> t2 and t3 still can't be handled concurrently. >> >> fio test script: startdelay is used to avoid queue merging >> [global] >> filename=/dev/nvme0n1 >> allow_mounted_write=0 >> ioengine=psync >> direct=1 >> ioscheduler=bfq >> offset_increment=10g >> group_reporting >> rw=randwrite >> bs=4k >> >> [test1] >> numjobs=1 >> >> [test2] >> startdelay=1 >> numjobs=1 >> >> [test3] >> startdelay=2 >> numjobs=1 >> >> [test4] >> startdelay=3 >> numjobs=1 >> >> [test5] >> startdelay=4 >> numjobs=1 >> >> [test6] >> startdelay=5 >> numjobs=1 >> >> [test7] >> startdelay=6 >> numjobs=1 >> >> [test8] >> startdelay=7 >> numjobs=1 >> >> test result: >> running fio on root cgroup >> v5.17-rc6: 550 Mib/s >> v5.17-rc6-patched: 550 Mib/s >> >> running fio on non-root cgroup >> v5.17-rc6: 349 Mib/s >> v5.17-rc6-patched: 550 Mib/s >> >> Yu Kuai (11): >> block, bfq: add new apis to iterate bfq entities >> block, bfq: apply news apis where root group is not expected >> block, bfq: cleanup for __bfq_activate_requeue_entity() >> block, bfq: move the increasement of 'num_groups_with_pending_reqs' to >> it's caller >> block, bfq: count root group into 'num_groups_with_pending_reqs' >> block, bfq: do not idle if only one cgroup is activated >> block, bfq: only count parent bfqg when bfqq is activated >> block, bfq: record how many queues have pending requests in bfq_group >> block, bfq: move forward __bfq_weights_tree_remove() >> block, bfq: decrease 'num_groups_with_pending_reqs' earlier >> block, bfq: cleanup bfqq_group() >> >> block/bfq-cgroup.c | 13 +++---- >> block/bfq-iosched.c | 87 +++++++++++++++++++++++---------------------- >> block/bfq-iosched.h | 41 +++++++++++++-------- >> block/bfq-wf2q.c | 56 +++++++++++++++-------------- >> 4 files changed, 106 insertions(+), 91 deletions(-) >>
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