* ib_read_lat question
@ 2013-02-21 17:50 Steve Wise
[not found] ` <51265E60.1070609-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org>
0 siblings, 1 reply; 4+ messages in thread
From: Steve Wise @ 2013-02-21 17:50 UTC (permalink / raw)
To: idos-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb
Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Hey Ido,
ib_read_lat displays RTT latency, while the other lat programs display
RTT/2. Is this intended? Or is read_lat.c/print_report() missing a
divide-by-two?
Thanks,
Steve.
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^ permalink raw reply [flat|nested] 4+ messages in thread[parent not found: <51265E60.1070609-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org>]
* RE: ib_read_lat question [not found] ` <51265E60.1070609-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org> @ 2013-02-21 18:27 ` Hefty, Sean [not found] ` <1828884A29C6694DAF28B7E6B8A823736F35235F-P5GAC/sN6hmkrb+BlOpmy7fspsVTdybXVpNB7YpNyf8@public.gmane.org> 0 siblings, 1 reply; 4+ messages in thread From: Hefty, Sean @ 2013-02-21 18:27 UTC (permalink / raw) To: Steve Wise, idos-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb@public.gmane.org Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org > ib_read_lat displays RTT latency, while the other lat programs display > RTT/2. Is this intended? Or is read_lat.c/print_report() missing a > divide-by-two? The tests should measure how long it takes the data to reach the destination. For writes/sends, that would be RTT/2. For reads, the destination is local, so you should want RTT. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html ^ permalink raw reply [flat|nested] 4+ messages in thread
[parent not found: <1828884A29C6694DAF28B7E6B8A823736F35235F-P5GAC/sN6hmkrb+BlOpmy7fspsVTdybXVpNB7YpNyf8@public.gmane.org>]
* Re: ib_read_lat question [not found] ` <1828884A29C6694DAF28B7E6B8A823736F35235F-P5GAC/sN6hmkrb+BlOpmy7fspsVTdybXVpNB7YpNyf8@public.gmane.org> @ 2013-02-21 18:34 ` Steve Wise [not found] ` <512668BF.4030908-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org> 0 siblings, 1 reply; 4+ messages in thread From: Steve Wise @ 2013-02-21 18:34 UTC (permalink / raw) To: Hefty, Sean Cc: idos-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb@public.gmane.org, linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Troy Leedberg On 2/21/2013 12:27 PM, Hefty, Sean wrote: >> ib_read_lat displays RTT latency, while the other lat programs display >> RTT/2. Is this intended? Or is read_lat.c/print_report() missing a >> divide-by-two? > The tests should measure how long it takes the data to reach the destination. For writes/sends, that would be RTT/2. For reads, the destination is local, so you should want RTT. Guess that makes sense. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html ^ permalink raw reply [flat|nested] 4+ messages in thread
[parent not found: <512668BF.4030908-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org>]
* Re: ib_read_lat question [not found] ` <512668BF.4030908-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org> @ 2013-02-27 8:46 ` Ido Shamai 0 siblings, 0 replies; 4+ messages in thread From: Ido Shamai @ 2013-02-27 8:46 UTC (permalink / raw) To: Steve Wise Cc: Hefty, Sean, linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Troy Leedberg On 2/21/2013 8:34 PM, Steve Wise wrote: > On 2/21/2013 12:27 PM, Hefty, Sean wrote: >>> ib_read_lat displays RTT latency, while the other lat programs display >>> RTT/2. Is this intended? Or is read_lat.c/print_report() missing a >>> divide-by-two? >> The tests should measure how long it takes the data to reach the >> destination. For writes/sends, that would be RTT/2. For reads, the >> destination is local, so you should want RTT. > > Guess that makes sense. > Yes, to me too. Thanks Sean -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2013-02-27 8:46 UTC | newest]
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2013-02-21 17:50 ib_read_lat question Steve Wise
[not found] ` <51265E60.1070609-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org>
2013-02-21 18:27 ` Hefty, Sean
[not found] ` <1828884A29C6694DAF28B7E6B8A823736F35235F-P5GAC/sN6hmkrb+BlOpmy7fspsVTdybXVpNB7YpNyf8@public.gmane.org>
2013-02-21 18:34 ` Steve Wise
[not found] ` <512668BF.4030908-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org>
2013-02-27 8:46 ` Ido Shamai
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