public inbox for linux-rdma@vger.kernel.org
 help / color / mirror / Atom feed
From: bugzilla-daemon-590EEB7GvNiWaY/ihj7yzEB+6BGkLq7r@public.gmane.org
To: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: [Bug 109391] New: Packet and byte counters only 32bit
Date: Tue, 15 Dec 2015 10:18:02 +0000	[thread overview]
Message-ID: <bug-109391-11804@https.bugzilla.kernel.org/> (raw)

https://bugzilla.kernel.org/show_bug.cgi?id=109391

            Bug ID: 109391
           Summary: Packet and byte counters only 32bit
           Product: Drivers
           Version: 2.5
    Kernel Version: git HEAD
          Hardware: All
                OS: Linux
              Tree: Mainline
            Status: NEW
          Severity: normal
          Priority: P1
         Component: Infiniband/RDMA
          Assignee: drivers_infiniband-rdma-ztI5WcYan/vQLgFONoPN62D2FQJk+8+b@public.gmane.org
          Reporter: philipp.marek-63ez5xqkn6DQT0dZR+AlfA@public.gmane.org
        Regression: No

Trying to find packet and byte counters for the RDMA transports I stumbled upon
this directory:

    /sys/class/infiniband/mlx5_1/ports/1/counters/

This seems to have all the requested data; but, looking again, I can see

    port_rcv_data: 4294967295

which looks awful.


And indeed, in 

   
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/drivers/infiniband/core/sysfs.c#n401

there's a 32bit width, with explicit code in

   
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/drivers/infiniband/hw/qib/qib_mad.c#n1507

to cap on that limit...


That is useless for the upcoming speeds. The MLX5 driver can drive Connect-X4
cards which go 100GBit/sec; that is 11GByte/sec, which means that the 32bit
counter will overflow ~3 times a second. So it can't be monitored.


Please provide 64bit counters (for packets and bytes, at least)!

Thanks a lot.

-- 
You are receiving this mail because:
You are watching the assignee of the bug.
--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

                 reply	other threads:[~2015-12-15 10:18 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=bug-109391-11804@https.bugzilla.kernel.org/ \
    --to=bugzilla-daemon-590eeb7gvniway/ihj7yzeb+6bgklq7r@public.gmane.org \
    --cc=linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox