Re: [PATCH v11 0/3] Fix cmdline_poll and testpmd signal handling

[Stephen Hemminger <stephen@networkplumber.org>]

On Mon, 13 Mar 2023 10:34:55 +0000
"Ling, WeiX" <weix.ling@intel.com> wrote:

> > -----Original Message-----
> > From: Tal Shnaiderman <talshn@nvidia.com>
> > Sent: Monday, March 13, 2023 1:18 AM
> > To: NBU-Contact-Thomas Monjalon (EXTERNAL) <thomas@monjalon.net>;
> > Stephen Hemminger <stephen@networkplumber.org>; Pier Damouny
> > <pdamouny@nvidia.com>
> > Cc: dev@dpdk.org; stable@dpdk.org; ferruh.yigit@amd.com; Singh, Aman
> > Deep <aman.deep.singh@intel.com>; Zhang, Yuying
> > <yuying.zhang@intel.com>; Raslan Darawsheh <rasland@nvidia.com>
> > Subject: RE: [PATCH v11 0/3] Fix cmdline_poll and testpmd signal handling
> >   
> > > Subject: Re: [PATCH v11 0/3] Fix cmdline_poll and testpmd signal
> > > handling
> > >
> > > External email: Use caution opening links or attachments
> > >
> > >
> > > 19/02/2023 18:53, Stephen Hemminger:  
> > > > On Fri,  3 Feb 2023 11:14:06 -0800
> > > > Stephen Hemminger <stephen@networkplumber.org> wrote:
> > > >  
> > > > > This patchset keeps uncovering bad practices in the cmdline
> > > > > library around end of file and signal handling.
> > > > >
> > > > > Stephen Hemminger (3):
> > > > >   cmdline: make rdline status not private
> > > > >   cmdline: handle EOF in cmdline_poll
> > > > >   testpmd: cleanup cleanly from signal
> > > > >
> > > > >  app/test-pmd/cmdline.c        | 29 +++++--------
> > > > >  app/test-pmd/testpmd.c        | 77 ++++++++++++++++-------------------
> > > > >  app/test-pmd/testpmd.h        |  1 +
> > > > >  lib/cmdline/cmdline.c         | 11 +++--
> > > > >  lib/cmdline/cmdline.h         |  6 +++
> > > > >  lib/cmdline/cmdline_private.h |  6 ---
> > > > >  6 files changed, 62 insertions(+), 68 deletions(-)
> > > > >  
> > > >
> > > > Could this please be merged for 23.03?
> > > > There are Ack's.
> > > > The only CI failure is a bogus performance test failure.  
> > >
> > > There was no review from testpmd maintainers.
> > >
> > > I've added Cc: stable@dpdk.org.
> > > Applied, thanks.
> > >  
> > Hi,
> > 
> > Commit "testpmd: cleanup cleanly from signal" from this series breaks
> > TestPMD's interactive mode on Windows.
> > 
> > See https://bugs.dpdk.org/show_bug.cgi?id=1180  
> 
> Hi Stephen,
> 
> I found an issue based this commit(0fd1386c: app/testpmd: cleanup cleanly from signal).
> 
> The packets can't loop in 2 testpmd after start dpdk-pdump to capture packets Immediately (less than 1 second).
> 
> Steps:
> 
> 1. Bind 1 CBDMA channel to vfio-pci, then start vhost-user as back-end:
> 
> x86_64-native-linuxapp-gcc/app/dpdk-testpmd -l 28-36 -n 4 -a 0000:80:04.0 --file-prefix=vhost   \
> --vdev 'eth_vhost0,iface=vhost-net0,queues=8,client=1,\
> dmas=[txq0@0000:80:04.0;txq1@0000:80:04.0;txq2@0000:80:04.0;txq3@0000:80:04.0;txq4@0000:80:04.0;txq5@0000:80:04.0;rxq2@0000:80:04.0;rxq3@0000:80:04.0;rxq4@0000:80:04.0;rxq5@0000:80:04.0;rxq6@0000:80:04.0;rxq7@0000:80:04.0]'
> --iova=va -- -i --nb-cores=4 --rxq=8 --txq=8 --txd=1024 --rxd=1024
> 
> 2. Start virtio-user as front-end:
> 
> x86_64-native-linuxapp-gcc/app/dpdk-testpmd -l 38-42 -n 4  --file-prefix=virtio-user0 --no-pci   \
> --vdev=net_virtio_user0,mac=00:11:22:33:44:10,path=./vhost-net0,queues=8,mrg_rxbuf=1,in_order=1,packed_vq=1,server=1 \
> -- -i --nb-cores=4 --rxq=8 --txq=8 --txd=1024 --rxd=1024
> testpmd>set fwd csum
> testpmd>start  
> 
> 3.Start dpdk-pdump to capture packets:
> 
> x86_64-native-linuxapp-gcc/app/dpdk-pdump  -v --file-prefix=virtio-user0 -- \
> --pdump  'device_id=net_virtio_user0,queue=0,rx-dev=/root/dpdk/pdump-rx-q0.pcap,mbuf-size=8000' --pdump  \
> 'device_id=net_virtio_user0,queue=1,rx-dev=/root/dpdk/pdump-rx-q1.pcap,mbuf-size=8000'
> 
> 4.Set forwarding mode and send packets from vhost-user(execute this step must immediately, we use the automation script to do, it can be reproduced, and if I add time.sleep(1) before this step, it works well):
> 
> testpmd>set fwd mac
> testpmd>set txpkts 64,64,64,2000,2000,2000
> testpmd>set burst 1
> testpmd>start tx_first 1
> testpmd>show port stats 0  
> 
> And I try to modify the follows code, then re-build DPDK, it works well. Maybe it's not a good method, just for your reference.
> 
> diff --git a/lib/cmdline/cmdline_os_unix.c b/lib/cmdline/cmdline_os_unix.c
> index 64a945a34f..ede8289244 100644
> --- a/lib/cmdline/cmdline_os_unix.c
> +++ b/lib/cmdline/cmdline_os_unix.c
> @@ -37,7 +37,7 @@ cmdline_poll_char(struct cmdline *cl)
>         pfd.events = POLLIN;
>         pfd.revents = 0; -       return poll(&pfd, 1, 0);
> +       return poll(&pfd, 1, -1);
> } ssize_t


Thanks, cmdline_poll() existed a long time but was never used by any part of DPDK
until now. My preference is to get the old cmdline_read_char() working and just
remove it.