svn commit: r315662 - in head: contrib/bsnmp/snmp_mibII contrib/ipfilter/ipsend lib/libprocstat sys/netinet sys/sys usr.bin/netstat usr.bin/sockstat usr.bin/systat usr.sbin/tcpdrop usr.sbin/trpt

[Cy Schubert]

In message <20170321201838.GG86500 at zxy.spb.ru>, Slawa Olhovchenkov writes:
> On Tue, Mar 21, 2017 at 01:07:42PM -0700, Cy Schubert wrote:
> 
> > In message <20170321195202.GF86500 at zxy.spb.ru>, Slawa Olhovchenkov writes:
> > > On Tue, Mar 21, 2017 at 11:50:04AM -0700, Gleb Smirnoff wrote:
> > > 
> > > >   John,
> > > > 
> > > > On Tue, Mar 21, 2017 at 10:40:34AM -0700, John Baldwin wrote:
> > > > J> First, this is a very good change and long overdue in divorcing the
> > > > J> user-facing structure for live system reporting vs the kernel struct
> ure.
> > > > J> 
> > > > J> However, I realize you don't use info from netstat when debugging ke
> rnel
> > > > J> crash dumps, but other people _do_.  It's ok if the kvm bits of nets
> tat
> > > > J> require a matching kernel and thus require recompiling everytime the
>  ABI
> > > > J> changes, but it is useful to have them.  Please restore those.
> > > > 
> > > > I have very much anticipated this comment from you, John.
> > > > 
> > > > I would like to remind you, that we have had this very exact conversati
> on
> > > > back when I removed kvm support from netstat/route.c. Let me search the
> > > > archives:
> > > > 
> > > > https://lists.freebsd.org/pipermail/svn-src-head/2015-April/070480.html
> > > > 
> > > > This conversation has had a continuation on IRC, which I don't archive.
> > > > 
> > > > AFAIR, first I told that with all my involvement into networking stack,
> > > > I never ever had experienced a need to run route stats on a core. The
> > > > debugger were the only useful tool. And that opinion was seconded by
> > > > other network hackers. Then we discussed that a proper tool chould use
> > > > dynamic type parsing and not kvm(3). You said that future gdb has pytho
> n
> > > > scripting and that would work fine. Meanwhile, you insisted that I rest
> ore
> > > > the functionality. I resisted to put kvm(3) back into netstat/route.c, 
> and
> > > > instead I created a gdb script that prints exactly what 'nestat -anr -M
>  cor
> > > e'
> > > > prints. And I committed the script just to satisfy your demand:
> > > > 
> > > > tools/debugscripts/netstat-anr.gdb
> > > > 
> > > > Can you please fairly answer, have you (or anyone else) ever used the
> > > > script during these 2 years?
> > > > 
> > > > I believe, the inpcb/tcpcb printing from a core functionality has the
> > > > same level of real usefulness. I could create the same script for pcbs,
> > > > and I am afraid it is going to share fate of netstat-anr.gdb.
> > > 
> > > How long run this script for core file w/ 40K TCP connections?
> > 
> > Would it be possible to replace this script with new DTrace probes and a 
> > DTrace script?
> 
> DTrace probes in /etc/rc.d/savecore? Realy?
> 

Sorry, rushing through the noon hour. I should have read this thread more 
carefully.


-- 
Cheers,
Cy Schubert <Cy.Schubert at cschubert.com>
FreeBSD UNIX:  <cy at FreeBSD.org>   Web:  http://www.FreeBSD.org

	The need of the many outweighs the greed of the few.