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Date:      Thu, 09 Jan 2014 18:29:11 +0200
From:      Alexander Motin <mav@FreeBSD.org>
To:        Adrian Chadd <adrian@freebsd.org>
Cc:        "svn-src-head@freebsd.org" <svn-src-head@freebsd.org>, "svn-src-all@freebsd.org" <svn-src-all@freebsd.org>, "src-committers@freebsd.org" <src-committers@freebsd.org>
Subject:   Re: svn commit: r260486 - head/etc/defaults
Message-ID:  <52CECE57.4040002@FreeBSD.org>
In-Reply-To: <CAJ-Vmo=exgGkzq6sFrgBzgZB0TjNJRvZ3eo6=Fs%2BU1Rp354pvg@mail.gmail.com>
References:  <201401091555.s09Fttju004938@svn.freebsd.org>	<CAJ-VmokAfJVwHqdV=GojLj2EeDgU-njgVedWUBM6-Zv1mDgffw@mail.gmail.com>	<52CEC79F.2090708@FreeBSD.org> <CAJ-Vmo=exgGkzq6sFrgBzgZB0TjNJRvZ3eo6=Fs%2BU1Rp354pvg@mail.gmail.com>

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On 09.01.2014 18:18, Adrian Chadd wrote:
> Depends if you're thinking locally or globally.
>
> Locally - for nfs? not a big deal.
>
> Globally - NFS, ZFS, GELI, geom/cam, NIC, etc.. suddenly your machine
> could default to having a couple thousand worker threads just for a
> HBA and a 10GE NIC. That's a little nuts.

So, what is your point? Each NFS thread (unlike GEOM or CAM) executes 
only _one_ request at a time. Would you like your 128-core/many-spindle 
system executed only 4 synchronous requests at a time?

> On 9 January 2014 08:00, Alexander Motin <mav@freebsd.org> wrote:
>> On 09.01.2014 17:57, Adrian Chadd wrote:
>>>
>>> .. so with say, 128 core boxes showing up, is this really a good default?
>>
>>
>> And what is the price? 16K+ of KVA per thread for thread stack, etc? 4
>> threads is probably much worse default there. May be nfsd's default could be
>> tuned, but obviously it should not be hardcoded value.
>>
>>
>>> On 9 January 2014 07:55, Alexander Motin <mav@freebsd.org> wrote:
>>>>
>>>> Author: mav
>>>> Date: Thu Jan  9 15:55:55 2014
>>>> New Revision: 260486
>>>> URL: http://svnweb.freebsd.org/changeset/base/260486
>>>>
>>>> Log:
>>>>     Remove very low default limit of 4 nfsd threads.  nfsd's own default
>>>> is
>>>>     8 * hw.ncpu, that sounds more appropriate for these SMP/NCQ/... days.
>>>>
>>>> Modified:
>>>>     head/etc/defaults/rc.conf
>>>>
>>>> Modified: head/etc/defaults/rc.conf
>>>>
>>>> ==============================================================================
>>>> --- head/etc/defaults/rc.conf   Thu Jan  9 15:38:28 2014        (r260485)
>>>> +++ head/etc/defaults/rc.conf   Thu Jan  9 15:55:55 2014        (r260486)
>>>> @@ -311,7 +311,7 @@ nfs_client_enable="NO"              # This host is a
>>>>    nfs_access_cache="60"          # Client cache timeout in seconds
>>>>    nfs_server_enable="NO"         # This host is an NFS server (or NO).
>>>>    oldnfs_server_enable="NO"      # Run the old NFS server (YES/NO).
>>>> -nfs_server_flags="-u -t -n 4"  # Flags to nfsd (if enabled).
>>>> +nfs_server_flags="-u -t"       # Flags to nfsd (if enabled).
>>>>    mountd_enable="NO"             # Run mountd (or NO).
>>>>    mountd_flags="-r"              # Flags to mountd (if NFS server
>>>> enabled).
>>>>    weak_mountd_authentication="NO"        # Allow non-root mount requests
>>>> to be served.
>>
>>
>>
>> --
>> Alexander Motin


-- 
Alexander Motin



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