I forward networking bugs to the maintainers.
Netdev does not use bugzilla, not sure if NFS does.
Begin forwarded message:
Date: Thu, 18 Apr 2024 00:00:22 +0000
From: [email protected]
To: [email protected]
Subject: [Bug 218743] New: NFS-RDMA-Connected Regression Found on Upstream Linux 6.9-rc1
https://bugzilla.kernel.org/show_bug.cgi?id=218743
Bug ID: 218743
Summary: NFS-RDMA-Connected Regression Found on Upstream Linux
6.9-rc1
Product: Networking
Version: 2.5
Kernel Version: 6.9-rc1
Hardware: Intel
OS: Linux
Status: NEW
Severity: high
Priority: P3
Component: Other
Assignee: [email protected]
Reporter: [email protected]
CC: [email protected]
Regression: Yes
Bisected e084ee673c77cade06ab4c2e36b5624c82608b8c
commit-id:
On the Linux 6.9-rc1 kernel there is a performance regression for NFS file
transfers when Connected IPoIB mode is enabled. The network switch is OPA
(Omnipath Architecture).
The most recent good commit in my bisection was the v6.8 mainline kernel
(e8f897f4afef0031fe618a8e94127a0934896aba). Bisecting from v6.8 to v6.9-rc1
showed me that "[e084ee673c77cade06ab4c2e36b5624c82608b8c] svcrdma: Add Write
chunk WRs to the RPC's Send WR chain" was indeed the culprit of the regression.
Here are the steps I ran to reproduce the issue:
1. Establish IPoIB Connected Mode on both client and host nodes:
"echo connected > /sys/class/net/ibs785/mode"
2. Start an NFS server on the host node:
"systemctl start opafm
sleep 10
systemctl start nfs-server
modprobe svcrdma
echo "rdma 20049" > /proc/fs/nfsd/portlist
mkdir -p /mnt/nfs_test
mount -t tmpfs -o size=4096M tmpfs /mnt/nfs_test
sudo exportfs -o fsid=0,rw,async,insecure,no_root_squash
192.168.2.0/255.255.255.0:/mnt/nfs_test_testrun/"
3. Ready the client node:
"mkdir -p /mnt/nfs_test
mount -o rdma,port=20049 192.168.2.1:/mnt/nfs_test_testrun
/mnt/nfs_test_testrun/"
4. Run the actual test from the client node:
"
#!/bin/bash
fsize=268435456
jfile=/dev/shm/run_nfs_test2.junk
tfile=/dev/shm/run_nfs_test2.tmp
nfsfile=/mnt/nfs_test_testrun/run_nfs_test2.junk
rm -r -f /mnt/nfs_test_testrun/
rm -f ${tfile}
rm -f ${jfile}
dd if=/dev/urandom iflag=fullblock of=${jfile} bs=1024 count=$((fsize/1024));
for i in {1..100}; do
cp ${jfile} ${nfsfile}; # Bottleneck 1
cp ${nfsfile} ${tfile}; # Bottleneck 2
cmp ${jfile} ${tfile};
rm -f ${tfile};
echo "DONE with iter ${i}"
done;
rm -f ${jfile};
rm -f ${tfile};
echo "Done";
"
On v6.8 I was seeing this test taking about 1m50s to complete, for all 10
iterations. On v6.9-rc1 it takes 3-7 minutes, and I also see these kernel
traces printed continuously in dmesg during this regression:
[23720.243905] INFO: task kworker/61:1:556 blocked for more than 122 seconds.
[23720.251709] Not tainted 6.9.0-rc1 #1
[23720.256387] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this
message.
[23720.265268] task:kworker/61:1 state:D stack:0 pid:556 tgid:556
ppid:2 flags:0x00004000
[23720.275822] Workqueue: events __svc_rdma_free [rpcrdma]
[23720.281803] Call Trace:
[23720.284630] <TASK>
[23720.287067] __schedule+0x210/0x660
[23720.291063] schedule+0x2c/0xb0
[23720.294668] schedule_timeout+0x146/0x160
[23720.299249] __wait_for_common+0x92/0x1d0
[23720.303828] ? __pfx_schedule_timeout+0x10/0x10
[23720.308987] __ib_drain_sq+0xfa/0x170 [ib_core]
[23720.314190] ? __pfx_ib_drain_qp_done+0x10/0x10 [ib_core]
[23720.320343] ib_drain_qp+0x71/0x80 [ib_core]
[23720.325232] __svc_rdma_free+0x28/0x100 [rpcrdma]
[23720.330604] process_one_work+0x196/0x3d0
[23720.335185] worker_thread+0x2fc/0x410
[23720.339470] ? __pfx_worker_thread+0x10/0x10
[23720.344336] kthread+0xdf/0x110
[23720.347941] ? __pfx_kthread+0x10/0x10
[23720.352225] ret_from_fork+0x30/0x50
[23720.356317] ? __pfx_kthread+0x10/0x10
[23720.360602] ret_from_fork_asm+0x1a/0x30
[23720.365083] </TASK>
--
You may reply to this email to add a comment.
You are receiving this mail because:
You are the assignee for the bug.
> On Apr 19, 2024, at 11:15 AM, Stephen Hemminger <[email protected]> wrote:
>
> I forward networking bugs to the maintainers.
> Netdev does not use bugzilla, not sure if NFS does.
>
> Begin forwarded message:
>
> Date: Thu, 18 Apr 2024 00:00:22 +0000
> From: [email protected]
> To: [email protected]
> Subject: [Bug 218743] New: NFS-RDMA-Connected Regression Found on Upstream Linux 6.9-rc1
>
>
> https://bugzilla.kernel.org/show_bug.cgi?id=218743
>
> Bug ID: 218743
> Summary: NFS-RDMA-Connected Regression Found on Upstream Linux
> 6.9-rc1
> Product: Networking
> Version: 2.5
> Kernel Version: 6.9-rc1
> Hardware: Intel
> OS: Linux
> Status: NEW
> Severity: high
> Priority: P3
> Component: Other
> Assignee: [email protected]
> Reporter: [email protected]
> CC: [email protected]
> Regression: Yes
> Bisected e084ee673c77cade06ab4c2e36b5624c82608b8c
> commit-id:
>
> On the Linux 6.9-rc1 kernel there is a performance regression for NFS file
> transfers when Connected IPoIB mode is enabled. The network switch is OPA
> (Omnipath Architecture).
>
> The most recent good commit in my bisection was the v6.8 mainline kernel
> (e8f897f4afef0031fe618a8e94127a0934896aba). Bisecting from v6.8 to v6.9-rc1
> showed me that "[e084ee673c77cade06ab4c2e36b5624c82608b8c] svcrdma: Add Write
> chunk WRs to the RPC's Send WR chain" was indeed the culprit of the regression.
>
>
> Here are the steps I ran to reproduce the issue:
> 1. Establish IPoIB Connected Mode on both client and host nodes:
> "echo connected > /sys/class/net/ibs785/mode"
>
>
> 2. Start an NFS server on the host node:
> "systemctl start opafm
> sleep 10
> systemctl start nfs-server
> modprobe svcrdma
> echo "rdma 20049" > /proc/fs/nfsd/portlist
> mkdir -p /mnt/nfs_test
> mount -t tmpfs -o size=4096M tmpfs /mnt/nfs_test
> sudo exportfs -o fsid=0,rw,async,insecure,no_root_squash
> 192.168.2.0/255.255.255.0:/mnt/nfs_test_testrun/"
>
>
> 3. Ready the client node:
> "mkdir -p /mnt/nfs_test
> mount -o rdma,port=20049 192.168.2.1:/mnt/nfs_test_testrun
> /mnt/nfs_test_testrun/"
>
>
> 4. Run the actual test from the client node:
> "
> #!/bin/bash
>
> fsize=268435456
> jfile=/dev/shm/run_nfs_test2.junk
> tfile=/dev/shm/run_nfs_test2.tmp
> nfsfile=/mnt/nfs_test_testrun/run_nfs_test2.junk
> rm -r -f /mnt/nfs_test_testrun/
> rm -f ${tfile}
> rm -f ${jfile}
>
> dd if=/dev/urandom iflag=fullblock of=${jfile} bs=1024 count=$((fsize/1024));
>
> for i in {1..100}; do
> cp ${jfile} ${nfsfile}; # Bottleneck 1
>
> cp ${nfsfile} ${tfile}; # Bottleneck 2
>
> cmp ${jfile} ${tfile};
>
> rm -f ${tfile};
> echo "DONE with iter ${i}"
> done;
>
> rm -f ${jfile};
> rm -f ${tfile};
> echo "Done";
> "
>
>
> On v6.8 I was seeing this test taking about 1m50s to complete, for all 10
> iterations. On v6.9-rc1 it takes 3-7 minutes, and I also see these kernel
> traces printed continuously in dmesg during this regression:
>
> [23720.243905] INFO: task kworker/61:1:556 blocked for more than 122 seconds.
> [23720.251709] Not tainted 6.9.0-rc1 #1
> [23720.256387] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this
> message.
> [23720.265268] task:kworker/61:1 state:D stack:0 pid:556 tgid:556
> ppid:2 flags:0x00004000
> [23720.275822] Workqueue: events __svc_rdma_free [rpcrdma]
> [23720.281803] Call Trace:
> [23720.284630] <TASK>
> [23720.287067] __schedule+0x210/0x660
> [23720.291063] schedule+0x2c/0xb0
> [23720.294668] schedule_timeout+0x146/0x160
> [23720.299249] __wait_for_common+0x92/0x1d0
> [23720.303828] ? __pfx_schedule_timeout+0x10/0x10
> [23720.308987] __ib_drain_sq+0xfa/0x170 [ib_core]
> [23720.314190] ? __pfx_ib_drain_qp_done+0x10/0x10 [ib_core]
> [23720.320343] ib_drain_qp+0x71/0x80 [ib_core]
> [23720.325232] __svc_rdma_free+0x28/0x100 [rpcrdma]
> [23720.330604] process_one_work+0x196/0x3d0
> [23720.335185] worker_thread+0x2fc/0x410
> [23720.339470] ? __pfx_worker_thread+0x10/0x10
> [23720.344336] kthread+0xdf/0x110
> [23720.347941] ? __pfx_kthread+0x10/0x10
> [23720.352225] ret_from_fork+0x30/0x50
> [23720.356317] ? __pfx_kthread+0x10/0x10
> [23720.360602] ret_from_fork_asm+0x1a/0x30
> [23720.365083] </TASK>
>
> --
> You may reply to this email to add a comment.
>
> You are receiving this mail because:
> You are the assignee for the bug.
>
Thanks, I've seen a performance regression on one system and
haven't been able to reproduce it elsewhere.
Please move this bug to Filesystems/NFS.
--
Chuck Lever