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Date: Sat, 27 Aug 2016 01:02:55 +0300
From: Slawa Olhovchenkov <slw@zxy.spb.ru>
To: Adrian Chadd <adrian@freebsd.org>
Cc: Bruce Simpson <bms@fastmail.net>, Ryan Stone <rysto32@gmail.com>,
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Subject: Re: svn commit: r304436 - in head: . sys/netinet
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On Fri, Aug 26, 2016 at 02:42:27PM -0700, Adrian Chadd wrote:

> On 26 August 2016 at 14:36, Slawa Olhovchenkov <slw@zxy.spb.ru> wrote:
> > On Fri, Aug 26, 2016 at 02:32:00PM -0700, Adrian Chadd wrote:
> >
> >> Hi,
> >>
> >> It's pcb lock contention.
> >
> > Not sure: only 5% of all time.
> > And same 5% for tcbhashsize = 65K and 256K.
> > Or you talk about some more thin effect?
> 
> You're in the inpcb lock from multiple places.

For tcp case I am found only 3 places: in_pcbdrop in_pcbremlists in_pcblookup_hash

> the tcbhashsize doesnt influence the pcb lock contention - it just
> affects how long you take doing lookups. iF your hash table is too
> small then you end up doing lots of O(n) walks of a hash bucket to
> find a pcb entry. :)

Hmm. I am not clearly understund you.
How originate pcb lock contention?
How I can see this (in pmc profile, in dtarce probese)?