Messages in this thread | | | Date | Sun, 13 Jul 2014 09:51:54 +0300 | From | Oren Twaig <> | Subject | Ping: Re: [PATCH v2] x86, vsmp: Remove is_vsmp_box() from apic_is_clustered_box() |
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ping On 07/06/2014 09:33 AM, Oren Twaig wrote: > Hi, > > Quick question: As I'm new at this (submitting patches), what is a reasonable > time to wait before ping-ing a patch ? > > Oren. > > On 06/29/2014 01:01 PM, Oren Twaig wrote: >> When a vSMP Foundation box is detected, the function apic_cluster_num() counts >> the number of APIC clusters found. If more than one found, a multi board >> configuration is assumed, and TSC marked as unstable. This behavior is >> incorrect as vSMP Foundation may use processors from single node only, attached >> to memory of other nodes - and such node may have more than one APIC cluster >> (typically any recent intel box has more than single APIC_CLUSTERID(x)). >> >> To fix this, we simply remove the code which detects a vSMP Foundation box and >> affects apic_is_clusted_box() return value. This can be done because later the >> kernel checks by itself if the TSC is stable using the >> check_tsc_sync_[source|target]() functions and marks TSC as unstable if needed. >> >> Acked-by: Shai Fultheim <shai@scalemp.com> >> Signed-off-by: Oren Twaig <oren@scalemp.com> >> --- >> diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h >> index 19b0eba..c100694 100644 >> --- a/arch/x86/include/asm/apic.h >> +++ b/arch/x86/include/asm/apic.h >> @@ -85,14 +85,6 @@ static inline bool apic_from_smp_config(void) >> #include <asm/paravirt.h> >> #endif >> >> -#ifdef CONFIG_X86_64 >> -extern int is_vsmp_box(void); >> -#else >> -static inline int is_vsmp_box(void) >> -{ >> - return 0; >> -} >> -#endif >> extern int setup_profiling_timer(unsigned int); >> >> static inline void native_apic_mem_write(u32 reg, u32 v) >> diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c >> index ad28db7..2b85bb9 100644 >> --- a/arch/x86/kernel/apic/apic.c >> +++ b/arch/x86/kernel/apic/apic.c >> @@ -2451,51 +2451,6 @@ static void apic_pm_activate(void) { } >> >> #ifdef CONFIG_X86_64 >> >> -static int apic_cluster_num(void) >> -{ >> - int i, clusters, zeros; >> - unsigned id; >> - u16 *bios_cpu_apicid; >> - DECLARE_BITMAP(clustermap, NUM_APIC_CLUSTERS); >> - >> - bios_cpu_apicid = early_per_cpu_ptr(x86_bios_cpu_apicid); >> - bitmap_zero(clustermap, NUM_APIC_CLUSTERS); >> - >> - for (i = 0; i < nr_cpu_ids; i++) { >> - /* are we being called early in kernel startup? */ >> - if (bios_cpu_apicid) { >> - id = bios_cpu_apicid[i]; >> - } else if (i < nr_cpu_ids) { >> - if (cpu_present(i)) >> - id = per_cpu(x86_bios_cpu_apicid, i); >> - else >> - continue; >> - } else >> - break; >> - >> - if (id != BAD_APICID) >> - __set_bit(APIC_CLUSTERID(id), clustermap); >> - } >> - >> - /* Problem: Partially populated chassis may not have CPUs in some of >> - * the APIC clusters they have been allocated. Only present CPUs have >> - * x86_bios_cpu_apicid entries, thus causing zeroes in the bitmap. >> - * Since clusters are allocated sequentially, count zeros only if >> - * they are bounded by ones. >> - */ >> - clusters = 0; >> - zeros = 0; >> - for (i = 0; i < NUM_APIC_CLUSTERS; i++) { >> - if (test_bit(i, clustermap)) { >> - clusters += 1 + zeros; >> - zeros = 0; >> - } else >> - ++zeros; >> - } >> - >> - return clusters; >> -} >> - >> static int multi_checked; >> static int multi; >> >> @@ -2540,20 +2495,7 @@ static void dmi_check_multi(void) >> int apic_is_clustered_box(void) >> { >> dmi_check_multi(); >> - if (multi) >> - return 1; >> - >> - if (!is_vsmp_box()) >> - return 0; >> - >> - /* >> - * ScaleMP vSMPowered boxes have one cluster per board and TSCs are >> - * not guaranteed to be synced between boards >> - */ >> - if (apic_cluster_num() > 1) >> - return 1; >> - >> - return 0; >> + return multi; >> } >> #endif >> >> > >
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