Re: [PATCH net] net/smc: Clear memory when release and reuse buffer

[Tony Lu <tonylu@linux.alibaba.com>]

On Fri, Nov 26, 2021 at 11:28:55AM -0800, Jakub Kicinski wrote:
> On Thu, 25 Nov 2021 20:28:59 +0800 Tony Lu wrote:
> > Currently, buffers are clear when smc create connections and reuse
> > buffer. It will slow down the speed of establishing new connection. In
> > most cases, the applications hope to establish connections as quickly as
> > possible.
> > 
> > This patch moves memset() from connection creation path to release and
> > buffer unuse path, this trades off between speed of establishing and
> > release.
> > 
> > Test environments:
> > - CPU Intel Xeon Platinum 8 core, mem 32 GiB, nic Mellanox CX4
> > - socket sndbuf / rcvbuf: 16384 / 131072 bytes
> > - w/o first round, 5 rounds, avg, 100 conns batch per round
> > - smc_buf_create() use bpftrace kprobe, introduces extra latency
> > 
> > Latency benchmarks for smc_buf_create():
> >   w/o patch : 19040.0 ns
> >   w/  patch :  1932.6 ns
> >   ratio :        10.2% (-89.8%)
> > 
> > Latency benchmarks for socket create and connect:
> >   w/o patch :   143.3 us
> >   w/  patch :   102.2 us
> >   ratio :        71.3% (-28.7%)
> > 
> > The latency of establishing connections is reduced by 28.7%.
> > 
> > Signed-off-by: Tony Lu <tonylu@linux.alibaba.com>
> > Reviewed-by: Wen Gu <guwen@linux.alibaba.com>
> 
> The tag in the subject seems incorrect, we tag things as [PATCH net] 
> if they are fixes, and as [PATCH net-next] if they are new features,
> code refactoring or performance improvements.
> 
> Is this a fix for a regression? In which case we need a Fixes tag to
> indicate where it was introduced. Otherwise it needs to be tagged as
> [PATCH net-next].
> 
> I'm assuming Karsten will take it via his tree, otherwise you'll need
> to repost.

Sorry to miss Graul’s email, he said he would put it in his own tree. I
would send v2 out if he needed. Thank you.

Thanks,
Tony Lu