Messages in this thread | | | From | David Wang <> | Subject | Re: [PATCH v2] x86/centaur: report correct CPU/cache topology | Date | Thu, 26 Apr 2018 17:52:37 +0800 |
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> -----Original Mail----- > Sender: Thomas Gleixner [mailto:tglx@linutronix.de] > Time: 2018年4月26日 17:12 > Receiver: David Wang <davidwang@zhaoxin.com> > CC: mingo@redhat.com; hpa@zytor.com; gregkh@linuxfoundation.org; > x86@kernel.org; linux-kernel@vger.kernel.org; brucechang@via- > alliance.com; cooperyan@zhaoxin.com; qiyuanwang@zhaoxin.com; > benjaminpan@viatech.com; lukelin@viacpu.com; timguo@zhaoxin.com > Subject: Re: [PATCH v2] x86/centaur: report correct CPU/cache topology > > On Wed, 25 Apr 2018, David Wang wrote: > > > > +static void early_init_centaur_mc(struct cpuinfo_x86 *c) { #ifdef > > +CONFIG_SMP > > + unsigned int eax, ebx, ecx, edx; > > + > > + if (c->cpuid_level < 4) > > + return; > > + > > + cpuid_count(4, 0, &eax, &ebx, &ecx, &edx); > > + if (eax & 0x1f) > > + c->x86_max_cores = (eax >> 26) + 1; > > + else > > + return; > > +#endif > > +} > > My review comment from last time still stands: > > > > This is a bad copy of intel_num_cpu_cores(). See for the subtle > > > difference. Please rename the intel function and move it to common.c > > In other words: > > Make a patch which moves intel_num_cpu_cores() into common.c. Rename > the function into something like detect_num_cpu_cores() and fix up the call > site in intel.c. > > Then add your patch and use the very same function. >
OK. I got it. > > + > > static void early_init_centaur(struct cpuinfo_x86 *c) { > > + early_init_centaur_mc(c); > > switch (c->x86) { > > #ifdef CONFIG_X86_32 > > case 5: > > @@ -146,6 +163,7 @@ static void centaur_detect_vmx_virtcap(struct > > cpuinfo_x86 *c) > > > > static void init_centaur(struct cpuinfo_x86 *c) { > > + unsigned int l2 = 0; > > #ifdef CONFIG_X86_32 > > char *name; > > u32 fcr_set = 0; > > @@ -161,6 +179,17 @@ static void init_centaur(struct cpuinfo_x86 *c) > > #endif > > early_init_centaur(c); > > > > + l2 = init_intel_cacheinfo(c); > > + > > + /* Detect legacy cache sizes if init_intel_cacheinfo did not */ > > + if (l2 == 0) { > > + cpu_detect_cache_sizes(c); > > + } > > Aside of the pointless parentheses, this really wants to be cleaned up as well. > > init_intel_cacheinfo() is called from the intel init code and it does the same > silly thing. > > So the right thing to do is in a separate patch first > > --- a/arch/x86/kernel/cpu/intel.c > +++ b/arch/x86/kernel/cpu/intel.c > @@ -679,12 +679,6 @@ static void init_intel(struct cpuinfo_x8 > > l2 = init_intel_cacheinfo(c); > > - /* Detect legacy cache sizes if init_intel_cacheinfo did not */ > - if (l2 == 0) { > - cpu_detect_cache_sizes(c); > - l2 = c->x86_cache_size; > - } > - > if (c->cpuid_level > 9) { > unsigned eax = cpuid_eax(10); > /* Check for version and the number of counters */ > --- a/arch/x86/kernel/cpu/intel_cacheinfo.c > +++ b/arch/x86/kernel/cpu/intel_cacheinfo.c > @@ -802,6 +802,11 @@ unsigned int init_intel_cacheinfo(struct > > c->x86_cache_size = l3 ? l3 : (l2 ? l2 : (l1i+l1d)); > > + /* Detect legacy cache sizes if the above did not work */ > + if (!l2) { > + cpu_detect_cache_sizes(c); > + l2 = c->x86_cache_size; > + } > return l2; > } > > Hmm? > > tglx > OK. I got it. Patch v3 will be sent later. Thank you. --- David
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