From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sasha Khapyorsky Subject: Re: [PATCH] opensm/osm_state_mgr.c: force heavy sweep when fabric consists of single switch Date: Fri, 13 Nov 2009 17:20:11 +0200 Message-ID: <20091113152011.GP7192@me> References: <4AF27EDB.6070604@dev.mellanox.co.il> <4AF6D619.8000908@gmail.com> <4AF7D040.2060807@dev.mellanox.co.il> <4AF7F22D.9010609@gmail.com> <4AF7F864.6030809@dev.mellanox.co.il> <4AF81F15.1080205@gmail.com> <4AFA80A5.8080809@dev.mellanox.co.il> <4AFBC1B7.8090509@gmail.com> <4AFC04A8.1040808@dev.mellanox.co.il> <694d48600911130024vd803e5fhf835690742f14ba7@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: <694d48600911130024vd803e5fhf835690742f14ba7-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Eli Dorfman Cc: kliteyn-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb@public.gmane.org, Line Holen , Linux RDMA List-Id: linux-rdma@vger.kernel.org On 10:24 Fri 13 Nov , Eli Dorfman wrote: > On Thu, Nov 12, 2009 at 2:50 PM, Yevgeny Kliteynik > wrote: > > Eli Dorfman (Voltaire) wrote: > >> > >> Yevgeny Kliteynik wrote: > >>> > >>> Eli Dorfman (Voltaire) wrote: > >>>> > >>>> Yevgeny Kliteynik wrote: > >>>>> > >>>>> Eli Dorfman (Voltaire) wrote: > >>>>>> > >>>>>> Yevgeny Kliteynik wrote: > >>>>>>> > >>>>>>> Eli Dorfman (Voltaire) wrote: > >>>>>>>> > >>>>>>>> Yevgeny Kliteynik wrote: > >>>>>>>>> > >>>>>>>>> Yevgeny Kliteynik wrote: > >>>>>>>>>> > >>>>>>>>>> Line Holen wrote: > >>>>>>>>>>> > >>>>>>>>>>> On 11/ 4/09 04:54 PM, Yevgeny Kliteynik wrote: > >>>>>>>>>>>> > >>>>>>>>>>>> Line Holen wrote: > >>>>>>>>>>>>> > >>>>>>>>>>>>> On 11/ 4/09 10:47 AM, Yevgeny Kliteynik wrote: > >>>>>>>>>>>>>> > >>>>>>>>>>>>>> Sasha Khapyorsky wrote: > >>>>>>>>>>>>>>> > >>>>>>>>>>>>>>> On 12:26 Tue 03 Nov =A0 =A0 , Yevgeny Kliteynik wrote= : This is a nice and productive discussion. But please remove a context which is not related to the current point - it helps to follow thread. [snip] > >> The PSC bit should be cleared before SM reads the PortInfo from th= at > >> switch. > > > > This may be true, but do you really want to require > > Set(SwitchInfo) *completion* before getting other PortInfo > > MADs from this switch? >=20 > I don't see any other good alternative and I'm sure this will solve > all race conditions. I agree with Eli - if we want to prevent PSC bit loss (which can be relevant for any subnet/SM topology), we need to clear it first and tha= n to fetch PortInfo. Obviously this may have some performance penalty, bu= t proper discovery is more important. > I suggest that when PSC bit is set in SwitchInfo response we will sen= d > Set(SwitchInfo) to clear the PSC bit and > in SwitchInfo response send Get(PortInfo) - this requires adding > another flag to the mad context. Another flag or reusing one of existing flag. > If PSC bit is not set or SM is not in Master state Get(PortInfo) will > be done in the immediately. >=20 > what do you think? Another potential issue is to avoid a secondary trap triggered sweep fo= r cases when PSC change is already cached. Basically looks like a right direction for me. Sasha -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" i= n the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html