RE: [PATCH net-next 04/10] RDMA/siw: use skb_crc32c() instead of __skb_checksum()

Bernard Metzler
2025-05-16T10:42:10Z

> -----Original Message-----
> From: Eric Biggers <ebiggers@kernel.org>
> Sent: Thursday, May 15, 2025 10:13 PM
> To: Bart Van Assche <bvanassche@acm.org>
> Cc: netdev@vger.kernel.org; Bernard Metzler <BMT@zurich.ibm.com>; linux-
> nvme@lists.infradead.org; linux-sctp@vger.kernel.org; linux-
> rdma@vger.kernel.org; linux-kernel@vger.kernel.org; Daniel Borkmann
> <daniel@iogearbox.net>; Marcelo Ricardo Leitner
> <marcelo.leitner@gmail.com>; Sagi Grimberg <sagi@grimberg.me>; Ard
> Biesheuvel <ardb@kernel.org>
> Subject: [EXTERNAL] Re: [PATCH net-next 04/10] RDMA/siw: use skb_crc32c()
> instead of __skb_checksum()
>
> On Thu, May 15, 2025 at 01:02:20PM -0700, Bart Van Assche wrote:
> > On 5/10/25 5:41 PM, Eric Biggers wrote:
> > > Instead of calling __skb_checksum() with a skb_checksum_ops struct that
> > > does CRC32C, just call the new function skb_crc32c(). This is faster
> > > and simpler.
> > Bernard, since you are the owner and author of the siw driver, please
> help
> > with reviewing this patch.
> >
> > Eric, do you already have a test case for the siw driver? If not,
> > multiple tests in the blktests framework use this driver intensively,
> > including the SRP tests that I wrote myself. See also
> > https%
> 3A__github.com_osandov_blktests&d=DwIBAg&c=BSDicqBQBDjDI9RkVyTcHQ&r=4ynb4Sj
> _4MUcZXbhvovE4tYSbqxyOwdSiLedP4yO55g&m=42RdxLC4OJSKYtu0EOtGxON-
> daxZpwd8xG9briOxYyywxa7RWrL-
> KukLFCucHn_c&s=dtz3xdRBYawI7d1FpWaWUV_QhDeExTyHGbPMZLxpzPQ&e= .
>
> No. I'll try that out when I have a chance.
>
> If the developers/maintainers of the driver could help test it, that would
> be a
> lot easier though. I've been cleaning up the CRC calls across the whole
> kernel,
> and it gets time-consuming when individual subsystems insist on me running
> their
> custom test suite(s) and providing subsystem-specific benchmarks.
>
> - Eric

I'll definitively test it. Sorry for the delay. You will hear from me
next days. If it comes to things like checksums, I always try to get
a setup where I can test against RMDA hardware (Chelsio). Hope to
find time over the WE.

Thanks,
Bernard.