[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: patch to support output synchronization under -j
From: |
Tim Murphy |
Subject: |
Re: patch to support output synchronization under -j |
Date: |
Fri, 15 Apr 2011 20:12:13 +0100 |
I wish I could play with one of those Connection machines and find out
about the bottlenecks at j=0.25*cpus that I can see on some machines
:-(
Regards,
Tim
On 15 April 2011 19:32, Howard Chu <address@hidden> wrote:
> Eli Zaretskii wrote:
>>>
>>> Date: Fri, 15 Apr 2011 10:37:13 -0400
>>> From: David Boyce<address@hidden>
>>> it's more a question of how many parallel jobs a given make process is
>>> managing since limits on file handles/descriptors are per process.
>>
>> What about people who use "make -j" without limits?
>
> They're idiots. I've never seen a machine that can handle more than 1.5x
> number of cores without getting bottlenecked by I/O or system scheduler.
> (And I've run this stuff on 1024 node Connection Machines, among other
> things...) Go above a certain threshold and you're only slowing yourself
> down.
>
>> It's not like having a 256-core machine is a fantasy that will not
>> happen in a few years. On my day job, we are already using 12 cores
>> and don't consider that "living on the edge".
>
> We've already seen bug reports from people running on machines with 4096
> cores, trying to run with -j8192 or somesuch. (Default pipe buffer is 4K
> which sets -j4096 as the practical limit without mucking with kernel
> params.)
>
> --
> -- Howard Chu
> CTO, Symas Corp. http://www.symas.com
> Director, Highland Sun http://highlandsun.com/hyc/
> Chief Architect, OpenLDAP http://www.openldap.org/project/
>
> _______________________________________________
> Bug-make mailing list
> address@hidden
> http://lists.gnu.org/mailman/listinfo/bug-make
>
--
You could help some brave and decent people to have access to
uncensored news by making a donation at:
http://www.thezimbabwean.co.uk/
- Re: patch to support output synchronization under -j, (continued)
- Re: patch to support output synchronization under -j, Eli Zaretskii, 2011/04/15
- Re: patch to support output synchronization under -j, Paul Smith, 2011/04/15
- Re: patch to support output synchronization under -j, David Boyce, 2011/04/15
- Re: patch to support output synchronization under -j, Eli Zaretskii, 2011/04/15
- Re: patch to support output synchronization under -j, Tim Murphy, 2011/04/15
- Re: patch to support output synchronization under -j, Paul Smith, 2011/04/15
- Re: patch to support output synchronization under -j, Eli Zaretskii, 2011/04/15
- Re: patch to support output synchronization under -j, Edward Welbourne, 2011/04/19
- Re: patch to support output synchronization under -j, David Boyce, 2011/04/19
- Re: patch to support output synchronization under -j, Howard Chu, 2011/04/15
- Re: patch to support output synchronization under -j,
Tim Murphy <=
- Re: patch to support output synchronization under -j, David Boyce, 2011/04/14
- Re: patch to support output synchronization under -j, Paul Smith, 2011/04/14
- Re: patch to support output synchronization under -j, Howard Chu, 2011/04/14
- Re: patch to support output synchronization under -j, Paul Smith, 2011/04/14
- Message not available
- Fwd: patch to support output synchronization under -j, Tim Murphy, 2011/04/14
- Re: patch to support output synchronization under -j, Tim Murphy, 2011/04/14
- Re: patch to support output synchronization under -j, Tim Murphy, 2011/04/14
- Re: patch to support output synchronization under -j, Paul Smith, 2011/04/14
- Re: patch to support output synchronization under -j, Tim Murphy, 2011/04/15
- Re: patch to support output synchronization under -j, Paul Smith, 2011/04/15