samba - Oct 2016 - Multichannel working at half speed with 2x NICs

Sorry for the delay Jeremy. I ran strace on the lowest pid for smbd (I ran
"pidof smbd" to get pids, and used the lowest one of the 4 or so that
came
up).

Command was "strace -f -o strace.log `ls /proc/2019/task/ | xargs -n 1 echo
-n " -p`". I then copied a 1.3GB file from the server to my client to
generate traffic. The resulting file was around 93k lines (15MB). I've
copied the first 2000 lines since it looks like the rest are
repeats/similar: http://pastebin.com/raw/2EJsk0An

I can provide the full file as well if required.

On Wed, Sep 28, 2016 at 1:54 PM Jeremy Allison <jra at samba.org> wrote:
> On Wed, Sep 28, 2016 at 07:45:03PM +0000, Kanchana Marasinghe via samba
> wrote:
> > Hi Jeremy,
> >
> > Is it safe to assume it's just "strace -p <pid>",
for the running samba
> > daemon?
>
> http://lichtman.io/strace-an-existing-multi-threaded-process/
>

On Wed, Sep 28, 2016 at 09:59:53PM +0000, Kanchana Marasinghe
wrote:
> Sorry for the delay Jeremy. I ran strace on the lowest pid for smbd (I ran
> "pidof smbd" to get pids, and used the lowest one of the 4 or so
that came
> up).
> 
> Command was "strace -f -o strace.log `ls /proc/2019/task/ | xargs -n 1
echo
> -n " -p`". I then copied a 1.3GB file from the server to my
client to
> generate traffic. The resulting file was around 93k lines (15MB). I've
> copied the first 2000 lines since it looks like the rest are
> repeats/similar: http://pastebin.com/raw/2EJsk0An
> 
> I can provide the full file as well if required.
I don't see any pread/pwrite calls - so this looks like a
meta-data heavy workload with few reads/writes (which means
multichannel won't help much).

In fact I don't see any reads/writes at all, which is
strange for a file copy :-).

On 2016-09-28 at 21:59 +0000, Kanchana Marasinghe via samba
wrote:
> Sorry for the delay Jeremy. I ran strace on the lowest pid for smbd (I ran
> "pidof smbd" to get pids, and used the lowest one of the 4 or so
that came
> up).
The lowest pid should be the main smbd.
That's not the one you need to strace:
you need to find out which smbd process belongs
to your session (with smbstatus) and strace _that_ pid.

That one should show reads/writes.

Cheers - Michael
> Command was "strace -f -o strace.log `ls /proc/2019/task/ | xargs -n 1
echo
> -n " -p`". I then copied a 1.3GB file from the server to my
client to
> generate traffic. The resulting file was around 93k lines (15MB). I've
> copied the first 2000 lines since it looks like the rest are
> repeats/similar: http://pastebin.com/raw/2EJsk0An
> 
> I can provide the full file as well if required.
> 
> On Wed, Sep 28, 2016 at 1:54 PM Jeremy Allison <jra at samba.org>
wrote:
> 
> > On Wed, Sep 28, 2016 at 07:45:03PM +0000, Kanchana Marasinghe via
samba
> > wrote:
> > > Hi Jeremy,
> > >
> > > Is it safe to assume it's just "strace -p
<pid>", for the running samba
> > > daemon?
> >
> > http://lichtman.io/strace-an-existing-multi-threaded-process/
> >
> -- 
> To unsubscribe from this list go to the following URL and read the
> instructions:  https://lists.samba.org/mailman/options/samba
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Hi Micheal,

I've done as you asked, and I got an strace. I ran strace while copying a
1.3GB mkv file from the server to my client. I've included only the first
2000 lines for brevity, but I do see a few pread calls in the log.

http://pastebin.com/raw/FjuppQcT

Hopefully that is what you're looking for.

Thanks,
Kanchana

On Sat, Oct 1, 2016 at 6:04 AM Michael Adam <obnox at samba.org> wrote:
> On 2016-09-28 at 21:59 +0000, Kanchana Marasinghe via samba wrote:
> > Sorry for the delay Jeremy. I ran strace on the lowest pid for smbd (I
> ran
> > "pidof smbd" to get pids, and used the lowest one of the 4
or so that
> came
> > up).
>
> The lowest pid should be the main smbd.
> That's not the one you need to strace:
> you need to find out which smbd process belongs
> to your session (with smbstatus) and strace _that_ pid.
>
> That one should show reads/writes.
>
> Cheers - Michael
>
> > Command was "strace -f -o strace.log `ls /proc/2019/task/ | xargs
-n 1
> echo
> > -n " -p`". I then copied a 1.3GB file from the server to my
client to
> > generate traffic. The resulting file was around 93k lines (15MB).
I've
> > copied the first 2000 lines since it looks like the rest are
> > repeats/similar: http://pastebin.com/raw/2EJsk0An
> >
> > I can provide the full file as well if required.
> >
> > On Wed, Sep 28, 2016 at 1:54 PM Jeremy Allison <jra at
samba.org> wrote:
> >
> > > On Wed, Sep 28, 2016 at 07:45:03PM +0000, Kanchana Marasinghe via
samba
> > > wrote:
> > > > Hi Jeremy,
> > > >
> > > > Is it safe to assume it's just "strace -p
<pid>", for the running
> samba
> > > > daemon?
> > >
> > > http://lichtman.io/strace-an-existing-multi-threaded-process/
> > >
> > --
> > To unsubscribe from this list go to the following URL and read the
> > instructions:  https://lists.samba.org/mailman/options/samba
>