Date: Mon, 9 Aug 2010 11:25:58 +0530 From: "Jayachandran C." <c.jayachandran@gmail.com> To: Attilio Rao <attilio@freebsd.org> Cc: src-committers@freebsd.org, John Baldwin <jhb@freebsd.org>, "Jayachandran C." <jchandra@freebsd.org>, svn-src-all@freebsd.org, Joe Landers <jlanders@vmware.com>, Randall Stewart <rrs@freebsd.org>, sbruno@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r208165 - in head/sys: kern mips/conf mips/include mips/mips mips/rmi mips/rmi/dev/xlr Message-ID: <AANLkTi=jkUiXStPV3Gq206GgmctM9%2B1ofbNWuh5CSeWw@mail.gmail.com> In-Reply-To: <AANLkTikAarFgbxgGu-8XG7gh6VidPoVGwva54NN4rcRF@mail.gmail.com> References: <201005161943.o4GJhnTo096839@svn.freebsd.org> <AANLkTikAarFgbxgGu-8XG7gh6VidPoVGwva54NN4rcRF@mail.gmail.com>
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On Mon, Aug 9, 2010 at 5:31 AM, Attilio Rao <attilio@freebsd.org> wrote: > 2010/5/16 Randall Stewart <rrs@freebsd.org>: >> Author: rrs >> Date: Sun May 16 19:43:48 2010 >> New Revision: 208165 >> URL: http://svn.freebsd.org/changeset/base/208165 >> >> Log: >> This pushes all of JC's patches that I have in place. I >> am now able to run 32 cores ok.. but I still will hang >> on buildworld with a NFS problem. I suspect I am missing >> a patch for the netlogic rge driver. >> >> JC check and see if I am missing anything except your >> core-mask changes > > >> Modified: head/sys/kern/subr_smp.c >> ============================================================================== >> --- head/sys/kern/subr_smp.c Sun May 16 19:25:56 2010 (r208164) >> +++ head/sys/kern/subr_smp.c Sun May 16 19:43:48 2010 (r208165) >> @@ -503,7 +503,10 @@ smp_topo_none(void) >> top = &group[0]; >> top->cg_parent = NULL; >> top->cg_child = NULL; >> - top->cg_mask = (1 << mp_ncpus) - 1; >> + if (mp_ncpus == sizeof(top->cg_mask) * 8) >> + top->cg_mask = -1; >> + else >> + top->cg_mask = (1 << mp_ncpus) - 1; >> top->cg_count = mp_ncpus; >> top->cg_children = 0; >> top->cg_level = CG_SHARE_NONE; >> > > ... and this is why I particulary hate big commits with complete lack > of technical details. > > This particulary chunk was supposed to fix a nasty and completely MI > bug that some users have already met (kern/148698). The complete lack > of details didn't help in identify the issue neither that it was a > valuable fix. > > The fix is, however, improper (there is no clear relationship between > the multiplication and why that happens) thus I would rather use what > Joe has reported in the PR. I was not aware of the PR when I sent this changes to rrs@, and this went as a part of MIPS SMP support for XLR which has 32 CPUs But I'm not sure that the current change is correct, cg_mask is of type cpumask_t and I don't think it is guaranteed to be 32 bit (as it is a machine dependent type). JC.
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