Date: Thu, 30 Apr 2009 19:14:46 -1000 (HST) From: Jeff Roberson <jroberson@jroberson.net> To: pluknet <pluknet@gmail.com>, jhb@freebsd.org Cc: freebsd-current@freebsd.org Subject: Re: cannot compile sched_ule without options SMP Message-ID: <alpine.BSF.2.00.0904301910550.981@desktop> In-Reply-To: <a31046fc0904302004r195750f2h586e08d9acf854d1@mail.gmail.com> References: <20090430013428.cb4f804b.nork@FreeBSD.org> <alpine.BSF.2.00.0904291329280.981@desktop> <a31046fc0904301232u1f0bdd15ybe9cdb345bce05a0@mail.gmail.com> <alpine.BSF.2.00.0904301207360.981@desktop> <a31046fc0904301939la407bfek2f342b06c7d3ba29@mail.gmail.com> <a31046fc0904302004r195750f2h586e08d9acf854d1@mail.gmail.com>
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On Fri, 1 May 2009, pluknet wrote: > 2009/5/1 pluknet <pluknet@gmail.com>: >> 2009/5/1 Jeff Roberson <jroberson@jroberson.net>: >>> On Thu, 30 Apr 2009, pluknet wrote: >>> >>>> 2009/4/30 Jeff Roberson <jroberson@jroberson.net>: >>>>> >>>>> On SMP machines you should now see output like this: >>>>> FreeBSD/SMP: Multiprocessor System Detected: 8 CPUs >>>>> FreeBSD/SMP: 1 package(s) x 4 core(s) x 2 SMT threads >>>>> >>>>> If you detect any irregularities with kern.sched.topology_spec or this >>>>> dmesg >>>>> line please report them. >>>>> >>>> >>>> Hi, Jeff. >>>> >>>> I have such mismatch. This is an Intel E7200. >>>> >>>> FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs >>>> FreeBSD/SMP: 1 package(s) x 1 core(s) x 2 HTT threads >>>> cpu0 (BSP): APIC ID: 0 >>>> cpu1 (AP/HT): APIC ID: 1 >>>> >>>> So it should be instead: 1 package(s) x 2 core(s) >>>> cpu0 (BSP): APIC ID: 0 >>>> cpu1 (AP): APIC ID: 1 >>> >>> Can you please repeat the following steps as I have done here: >>> >> >> (kgdb) p/x cpu_high >> $1 = 0x2 >> (kgdb) p/x cpu_cores >> $2 = 0x1 >> (kgdb) p/x cpu_logical >> $3 = 0x2 >> (kgdb) p/x cpu_feature >> $4 = 0xbfebfbff >> (kgdb) p/x logical_cpus >> $5 = 0x2 >> (kgdb) p/x hyperthreading_cpus >> $6 = 0x2 >> > > Follow up myself: > > What is embarrassing me is HTT feature enabled. May the reason be in a > buggy CPUID ? This is very curious. With older revisions did the system believe your CPUs were HTT? You can tell if you had sysctl machdep.hyperthreading_allowed or via the ULE kern.sched.topology_spec sysctl. I didn't realize there were any core2 CPUs without leaf 4 of cpuid. However, I didn't write the earlier hyperthread detection code. I'll see if I can get jhb to chime in. The HTT feature bit is set on many processors that don't have hyperthreads. So we need a secondary way of differentiating. I don't know what that is in this case. Thanks, Jeff > > -- > wbr, > pluknet >
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