Hello Grigory, We observed ~10% performance degradation with heap size set to unlimited for CFD applications.
You can measure your application performance with default and unlimited "limits" and select the best setting. Kind Regards. M On Mon, Sep 28, 2015 at 7:36 PM, Grigory Shamov <grigory.sha...@umanitoba.ca > wrote: > Hi All, > > > We have built OpenMPI (1.8.8., 1.10.0) against Mellanox OFED 2.4 and > corresponding MXM. When it runs now, it gives the following warning, per > process: > > [1443457390.911053] [myhist:5891 :0] mxm.c:185 MXM WARN The > 'ulimit -s' on the system is set to 'unlimited'. This may have negative > performance implications. Please set the heap size to the default value > (10240) > > We have ulimits for heap (as well as most of the other limits) set > unlimited because of applications that might possibly need a lot of RAM. > > The question is if we should do as MXM wants, or ignore it? Has anyone an > experience running recent OpenMPI with MXM enabled, and what kind of > ulimits do you have? Any suggestions/comments appreciated, thanks! > > > -- > Grigory Shamov > > Westgrid/ComputeCanada Site Lead > University of Manitoba > E2-588 EITC Building, > (204) 474-9625 > > > > _______________________________________________ > users mailing list > us...@open-mpi.org > Subscription: http://www.open-mpi.org/mailman/listinfo.cgi/users > Link to this post: > http://www.open-mpi.org/community/lists/users/2015/09/27697.php > -- Kind Regards, M.
