Hi Bernd,
Sorry for interruption.
I tested your fuse over io_uring patch set with libfuse null example,
the fuse over io_uring mode has better performance than the default
mode. e.g., the fio command is as below,
fio -direct=1 --filename=/mnt/singfile --rw=read -iodepth=1
--ioengine=libaio --bs=4k --size=4G --runtime=60 --numjobs=1
-name=test_fuse1
But, if I increased fio iodepth option, the fuse over io_uring mode
has worse performance than the default mode. e.g., the fio command is
as below,
fio -direct=1 --filename=/mnt/singfile --rw=read -iodepth=4
--ioengine=libaio --bs=4k --size=4G --runtime=60 --numjobs=1
-name=test_fuse2
The test result showed the fuse over io_uring mode cannot handle this
case properly. could you take a look at this issue? or this is design
issue?
I went through the related source code, I do not understand each
fuse_ring_queue thread has only one available ring entry? this design
will cause the above issue?
the related code is as follows,
dev_uring.c
1099
1100 queue = ring->queues[qid];
1101 if (!queue) {
1102 queue = fuse_uring_create_queue(ring, qid);
1103 if (!queue)
1104 return err;
1105 }
1106
1107 /*
1108 * The created queue above does not need to be destructed in
1109 * case of entry errors below, will be done at ring destruction time.
1110 */
1111
1112 ent = fuse_uring_create_ring_ent(cmd, queue);
1113 if (IS_ERR(ent))
1114 return PTR_ERR(ent);
1115
1116 fuse_uring_do_register(ent, cmd, issue_flags);
1117
1118 return 0;
1119 }
Thanks
Gang
