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author | Linus Torvalds <torvalds@linux-foundation.org> | 2010-02-28 18:15:31 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-02-28 18:15:31 (GMT) |
commit | d25e8dbdab203ed8b4fd0a174bb5259e35ecd87c (patch) | |
tree | 46aadc89806daebe509f35daa962114b7a730090 /arch | |
parent | 642c4c75a765d7a3244ab39c8e6fb09be21eca5b (diff) | |
parent | cfc9c0b450176a077205ef39092f0dc1a04e020a (diff) | |
download | linux-d25e8dbdab203ed8b4fd0a174bb5259e35ecd87c.tar.xz |
Merge branch 'oprofile-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'oprofile-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
oprofile/x86: fix msr access to reserved counters
oprofile/x86: use kzalloc() instead of kmalloc()
oprofile/x86: fix perfctr nmi reservation for mulitplexing
oprofile/x86: add comment to counter-in-use warning
oprofile/x86: warn user if a counter is already active
oprofile/x86: implement randomization for IBS periodic op counter
oprofile/x86: implement lsfr pseudo-random number generator for IBS
oprofile/x86: implement IBS cpuid feature detection
oprofile/x86: remove node check in AMD IBS initialization
oprofile/x86: remove OPROFILE_IBS config option
oprofile: remove EXPERIMENTAL from the config option description
oprofile: remove tracing build dependency
Diffstat (limited to 'arch')
-rw-r--r-- | arch/Kconfig | 18 | ||||
-rw-r--r-- | arch/x86/oprofile/nmi_int.c | 17 | ||||
-rw-r--r-- | arch/x86/oprofile/op_model_amd.c | 244 | ||||
-rw-r--r-- | arch/x86/oprofile/op_model_p4.c | 6 | ||||
-rw-r--r-- | arch/x86/oprofile/op_model_ppro.c | 17 | ||||
-rw-r--r-- | arch/x86/oprofile/op_x86_model.h | 20 |
6 files changed, 199 insertions, 123 deletions
diff --git a/arch/Kconfig b/arch/Kconfig index 9d055b4..06a1372 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -3,11 +3,9 @@ # config OPROFILE - tristate "OProfile system profiling (EXPERIMENTAL)" + tristate "OProfile system profiling" depends on PROFILING depends on HAVE_OPROFILE - depends on TRACING_SUPPORT - select TRACING select RING_BUFFER select RING_BUFFER_ALLOW_SWAP help @@ -17,20 +15,6 @@ config OPROFILE If unsure, say N. -config OPROFILE_IBS - bool "OProfile AMD IBS support (EXPERIMENTAL)" - default n - depends on OPROFILE && SMP && X86 - help - Instruction-Based Sampling (IBS) is a new profiling - technique that provides rich, precise program performance - information. IBS is introduced by AMD Family10h processors - (AMD Opteron Quad-Core processor "Barcelona") to overcome - the limitations of conventional performance counter - sampling. - - If unsure, say N. - config OPROFILE_EVENT_MULTIPLEX bool "OProfile multiplexing support (EXPERIMENTAL)" default n diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c index 3347f69..2c505ee 100644 --- a/arch/x86/oprofile/nmi_int.c +++ b/arch/x86/oprofile/nmi_int.c @@ -159,7 +159,7 @@ static int nmi_setup_mux(void) for_each_possible_cpu(i) { per_cpu(cpu_msrs, i).multiplex = - kmalloc(multiplex_size, GFP_KERNEL); + kzalloc(multiplex_size, GFP_KERNEL); if (!per_cpu(cpu_msrs, i).multiplex) return 0; } @@ -179,7 +179,6 @@ static void nmi_cpu_setup_mux(int cpu, struct op_msrs const * const msrs) if (counter_config[i].enabled) { multiplex[i].saved = -(u64)counter_config[i].count; } else { - multiplex[i].addr = 0; multiplex[i].saved = 0; } } @@ -189,25 +188,27 @@ static void nmi_cpu_setup_mux(int cpu, struct op_msrs const * const msrs) static void nmi_cpu_save_mpx_registers(struct op_msrs *msrs) { + struct op_msr *counters = msrs->counters; struct op_msr *multiplex = msrs->multiplex; int i; for (i = 0; i < model->num_counters; ++i) { int virt = op_x86_phys_to_virt(i); - if (multiplex[virt].addr) - rdmsrl(multiplex[virt].addr, multiplex[virt].saved); + if (counters[i].addr) + rdmsrl(counters[i].addr, multiplex[virt].saved); } } static void nmi_cpu_restore_mpx_registers(struct op_msrs *msrs) { + struct op_msr *counters = msrs->counters; struct op_msr *multiplex = msrs->multiplex; int i; for (i = 0; i < model->num_counters; ++i) { int virt = op_x86_phys_to_virt(i); - if (multiplex[virt].addr) - wrmsrl(multiplex[virt].addr, multiplex[virt].saved); + if (counters[i].addr) + wrmsrl(counters[i].addr, multiplex[virt].saved); } } @@ -303,11 +304,11 @@ static int allocate_msrs(void) int i; for_each_possible_cpu(i) { - per_cpu(cpu_msrs, i).counters = kmalloc(counters_size, + per_cpu(cpu_msrs, i).counters = kzalloc(counters_size, GFP_KERNEL); if (!per_cpu(cpu_msrs, i).counters) return 0; - per_cpu(cpu_msrs, i).controls = kmalloc(controls_size, + per_cpu(cpu_msrs, i).controls = kzalloc(controls_size, GFP_KERNEL); if (!per_cpu(cpu_msrs, i).controls) return 0; diff --git a/arch/x86/oprofile/op_model_amd.c b/arch/x86/oprofile/op_model_amd.c index 39686c2..6a58256 100644 --- a/arch/x86/oprofile/op_model_amd.c +++ b/arch/x86/oprofile/op_model_amd.c @@ -22,6 +22,9 @@ #include <asm/ptrace.h> #include <asm/msr.h> #include <asm/nmi.h> +#include <asm/apic.h> +#include <asm/processor.h> +#include <asm/cpufeature.h> #include "op_x86_model.h" #include "op_counter.h" @@ -43,15 +46,13 @@ static unsigned long reset_value[NUM_VIRT_COUNTERS]; -#ifdef CONFIG_OPROFILE_IBS - /* IbsFetchCtl bits/masks */ #define IBS_FETCH_RAND_EN (1ULL<<57) #define IBS_FETCH_VAL (1ULL<<49) #define IBS_FETCH_ENABLE (1ULL<<48) #define IBS_FETCH_CNT_MASK 0xFFFF0000ULL -/*IbsOpCtl bits */ +/* IbsOpCtl bits */ #define IBS_OP_CNT_CTL (1ULL<<19) #define IBS_OP_VAL (1ULL<<18) #define IBS_OP_ENABLE (1ULL<<17) @@ -59,7 +60,7 @@ static unsigned long reset_value[NUM_VIRT_COUNTERS]; #define IBS_FETCH_SIZE 6 #define IBS_OP_SIZE 12 -static int has_ibs; /* AMD Family10h and later */ +static u32 ibs_caps; struct op_ibs_config { unsigned long op_enabled; @@ -71,24 +72,52 @@ struct op_ibs_config { }; static struct op_ibs_config ibs_config; +static u64 ibs_op_ctl; -#endif +/* + * IBS cpuid feature detection + */ -#ifdef CONFIG_OPROFILE_EVENT_MULTIPLEX +#define IBS_CPUID_FEATURES 0x8000001b + +/* + * Same bit mask as for IBS cpuid feature flags (Fn8000_001B_EAX), but + * bit 0 is used to indicate the existence of IBS. + */ +#define IBS_CAPS_AVAIL (1LL<<0) +#define IBS_CAPS_RDWROPCNT (1LL<<3) +#define IBS_CAPS_OPCNT (1LL<<4) + +/* + * IBS randomization macros + */ +#define IBS_RANDOM_BITS 12 +#define IBS_RANDOM_MASK ((1ULL << IBS_RANDOM_BITS) - 1) +#define IBS_RANDOM_MAXCNT_OFFSET (1ULL << (IBS_RANDOM_BITS - 5)) -static void op_mux_fill_in_addresses(struct op_msrs * const msrs) +static u32 get_ibs_caps(void) { - int i; + u32 ibs_caps; + unsigned int max_level; - for (i = 0; i < NUM_VIRT_COUNTERS; i++) { - int hw_counter = op_x86_virt_to_phys(i); - if (reserve_perfctr_nmi(MSR_K7_PERFCTR0 + i)) - msrs->multiplex[i].addr = MSR_K7_PERFCTR0 + hw_counter; - else - msrs->multiplex[i].addr = 0; - } + if (!boot_cpu_has(X86_FEATURE_IBS)) + return 0; + + /* check IBS cpuid feature flags */ + max_level = cpuid_eax(0x80000000); + if (max_level < IBS_CPUID_FEATURES) + return IBS_CAPS_AVAIL; + + ibs_caps = cpuid_eax(IBS_CPUID_FEATURES); + if (!(ibs_caps & IBS_CAPS_AVAIL)) + /* cpuid flags not valid */ + return IBS_CAPS_AVAIL; + + return ibs_caps; } +#ifdef CONFIG_OPROFILE_EVENT_MULTIPLEX + static void op_mux_switch_ctrl(struct op_x86_model_spec const *model, struct op_msrs const * const msrs) { @@ -98,7 +127,7 @@ static void op_mux_switch_ctrl(struct op_x86_model_spec const *model, /* enable active counters */ for (i = 0; i < NUM_COUNTERS; ++i) { int virt = op_x86_phys_to_virt(i); - if (!counter_config[virt].enabled) + if (!reset_value[virt]) continue; rdmsrl(msrs->controls[i].addr, val); val &= model->reserved; @@ -107,10 +136,6 @@ static void op_mux_switch_ctrl(struct op_x86_model_spec const *model, } } -#else - -static inline void op_mux_fill_in_addresses(struct op_msrs * const msrs) { } - #endif /* functions for op_amd_spec */ @@ -122,18 +147,12 @@ static void op_amd_fill_in_addresses(struct op_msrs * const msrs) for (i = 0; i < NUM_COUNTERS; i++) { if (reserve_perfctr_nmi(MSR_K7_PERFCTR0 + i)) msrs->counters[i].addr = MSR_K7_PERFCTR0 + i; - else - msrs->counters[i].addr = 0; } for (i = 0; i < NUM_CONTROLS; i++) { if (reserve_evntsel_nmi(MSR_K7_EVNTSEL0 + i)) msrs->controls[i].addr = MSR_K7_EVNTSEL0 + i; - else - msrs->controls[i].addr = 0; } - - op_mux_fill_in_addresses(msrs); } static void op_amd_setup_ctrs(struct op_x86_model_spec const *model, @@ -144,7 +163,8 @@ static void op_amd_setup_ctrs(struct op_x86_model_spec const *model, /* setup reset_value */ for (i = 0; i < NUM_VIRT_COUNTERS; ++i) { - if (counter_config[i].enabled) + if (counter_config[i].enabled + && msrs->counters[op_x86_virt_to_phys(i)].addr) reset_value[i] = counter_config[i].count; else reset_value[i] = 0; @@ -152,9 +172,18 @@ static void op_amd_setup_ctrs(struct op_x86_model_spec const *model, /* clear all counters */ for (i = 0; i < NUM_CONTROLS; ++i) { - if (unlikely(!msrs->controls[i].addr)) + if (unlikely(!msrs->controls[i].addr)) { + if (counter_config[i].enabled && !smp_processor_id()) + /* + * counter is reserved, this is on all + * cpus, so report only for cpu #0 + */ + op_x86_warn_reserved(i); continue; + } rdmsrl(msrs->controls[i].addr, val); + if (val & ARCH_PERFMON_EVENTSEL0_ENABLE) + op_x86_warn_in_use(i); val &= model->reserved; wrmsrl(msrs->controls[i].addr, val); } @@ -169,9 +198,7 @@ static void op_amd_setup_ctrs(struct op_x86_model_spec const *model, /* enable active counters */ for (i = 0; i < NUM_COUNTERS; ++i) { int virt = op_x86_phys_to_virt(i); - if (!counter_config[virt].enabled) - continue; - if (!msrs->counters[i].addr) + if (!reset_value[virt]) continue; /* setup counter registers */ @@ -185,7 +212,60 @@ static void op_amd_setup_ctrs(struct op_x86_model_spec const *model, } } -#ifdef CONFIG_OPROFILE_IBS +/* + * 16-bit Linear Feedback Shift Register (LFSR) + * + * 16 14 13 11 + * Feedback polynomial = X + X + X + X + 1 + */ +static unsigned int lfsr_random(void) +{ + static unsigned int lfsr_value = 0xF00D; + unsigned int bit; + + /* Compute next bit to shift in */ + bit = ((lfsr_value >> 0) ^ + (lfsr_value >> 2) ^ + (lfsr_value >> 3) ^ + (lfsr_value >> 5)) & 0x0001; + + /* Advance to next register value */ + lfsr_value = (lfsr_value >> 1) | (bit << 15); + + return lfsr_value; +} + +/* + * IBS software randomization + * + * The IBS periodic op counter is randomized in software. The lower 12 + * bits of the 20 bit counter are randomized. IbsOpCurCnt is + * initialized with a 12 bit random value. + */ +static inline u64 op_amd_randomize_ibs_op(u64 val) +{ + unsigned int random = lfsr_random(); + + if (!(ibs_caps & IBS_CAPS_RDWROPCNT)) + /* + * Work around if the hw can not write to IbsOpCurCnt + * + * Randomize the lower 8 bits of the 16 bit + * IbsOpMaxCnt [15:0] value in the range of -128 to + * +127 by adding/subtracting an offset to the + * maximum count (IbsOpMaxCnt). + * + * To avoid over or underflows and protect upper bits + * starting at bit 16, the initial value for + * IbsOpMaxCnt must fit in the range from 0x0081 to + * 0xff80. + */ + val += (s8)(random >> 4); + else + val |= (u64)(random & IBS_RANDOM_MASK) << 32; + + return val; +} static inline void op_amd_handle_ibs(struct pt_regs * const regs, @@ -194,7 +274,7 @@ op_amd_handle_ibs(struct pt_regs * const regs, u64 val, ctl; struct op_entry entry; - if (!has_ibs) + if (!ibs_caps) return; if (ibs_config.fetch_enabled) { @@ -236,8 +316,7 @@ op_amd_handle_ibs(struct pt_regs * const regs, oprofile_write_commit(&entry); /* reenable the IRQ */ - ctl &= ~IBS_OP_VAL & 0xFFFFFFFF; - ctl |= IBS_OP_ENABLE; + ctl = op_amd_randomize_ibs_op(ibs_op_ctl); wrmsrl(MSR_AMD64_IBSOPCTL, ctl); } } @@ -246,41 +325,57 @@ op_amd_handle_ibs(struct pt_regs * const regs, static inline void op_amd_start_ibs(void) { u64 val; - if (has_ibs && ibs_config.fetch_enabled) { + + if (!ibs_caps) + return; + + if (ibs_config.fetch_enabled) { val = (ibs_config.max_cnt_fetch >> 4) & 0xFFFF; val |= ibs_config.rand_en ? IBS_FETCH_RAND_EN : 0; val |= IBS_FETCH_ENABLE; wrmsrl(MSR_AMD64_IBSFETCHCTL, val); } - if (has_ibs && ibs_config.op_enabled) { - val = (ibs_config.max_cnt_op >> 4) & 0xFFFF; - val |= ibs_config.dispatched_ops ? IBS_OP_CNT_CTL : 0; - val |= IBS_OP_ENABLE; + if (ibs_config.op_enabled) { + ibs_op_ctl = ibs_config.max_cnt_op >> 4; + if (!(ibs_caps & IBS_CAPS_RDWROPCNT)) { + /* + * IbsOpCurCnt not supported. See + * op_amd_randomize_ibs_op() for details. + */ + ibs_op_ctl = clamp(ibs_op_ctl, 0x0081ULL, 0xFF80ULL); + } else { + /* + * The start value is randomized with a + * positive offset, we need to compensate it + * with the half of the randomized range. Also + * avoid underflows. + */ + ibs_op_ctl = min(ibs_op_ctl + IBS_RANDOM_MAXCNT_OFFSET, + 0xFFFFULL); + } + if (ibs_caps & IBS_CAPS_OPCNT && ibs_config.dispatched_ops) + ibs_op_ctl |= IBS_OP_CNT_CTL; + ibs_op_ctl |= IBS_OP_ENABLE; + val = op_amd_randomize_ibs_op(ibs_op_ctl); wrmsrl(MSR_AMD64_IBSOPCTL, val); } } static void op_amd_stop_ibs(void) { - if (has_ibs && ibs_config.fetch_enabled) + if (!ibs_caps) + return; + + if (ibs_config.fetch_enabled) /* clear max count and enable */ wrmsrl(MSR_AMD64_IBSFETCHCTL, 0); - if (has_ibs && ibs_config.op_enabled) + if (ibs_config.op_enabled) /* clear max count and enable */ wrmsrl(MSR_AMD64_IBSOPCTL, 0); } -#else - -static inline void op_amd_handle_ibs(struct pt_regs * const regs, - struct op_msrs const * const msrs) { } -static inline void op_amd_start_ibs(void) { } -static inline void op_amd_stop_ibs(void) { } - -#endif - static int op_amd_check_ctrs(struct pt_regs * const regs, struct op_msrs const * const msrs) { @@ -355,8 +450,6 @@ static void op_amd_shutdown(struct op_msrs const * const msrs) } } -#ifdef CONFIG_OPROFILE_IBS - static u8 ibs_eilvt_off; static inline void apic_init_ibs_nmi_per_cpu(void *arg) @@ -405,45 +498,36 @@ static int init_ibs_nmi(void) return 1; } -#ifdef CONFIG_NUMA - /* Sanity check */ - /* Works only for 64bit with proper numa implementation. */ - if (nodes != num_possible_nodes()) { - printk(KERN_DEBUG "Failed to setup CPU node(s) for IBS, " - "found: %d, expected %d", - nodes, num_possible_nodes()); - return 1; - } -#endif return 0; } /* uninitialize the APIC for the IBS interrupts if needed */ static void clear_ibs_nmi(void) { - if (has_ibs) + if (ibs_caps) on_each_cpu(apic_clear_ibs_nmi_per_cpu, NULL, 1); } /* initialize the APIC for the IBS interrupts if available */ static void ibs_init(void) { - has_ibs = boot_cpu_has(X86_FEATURE_IBS); + ibs_caps = get_ibs_caps(); - if (!has_ibs) + if (!ibs_caps) return; if (init_ibs_nmi()) { - has_ibs = 0; + ibs_caps = 0; return; } - printk(KERN_INFO "oprofile: AMD IBS detected\n"); + printk(KERN_INFO "oprofile: AMD IBS detected (0x%08x)\n", + (unsigned)ibs_caps); } static void ibs_exit(void) { - if (!has_ibs) + if (!ibs_caps) return; clear_ibs_nmi(); @@ -463,7 +547,7 @@ static int setup_ibs_files(struct super_block *sb, struct dentry *root) if (ret) return ret; - if (!has_ibs) + if (!ibs_caps) return ret; /* model specific files */ @@ -473,7 +557,7 @@ static int setup_ibs_files(struct super_block *sb, struct dentry *root) ibs_config.fetch_enabled = 0; ibs_config.max_cnt_op = 250000; ibs_config.op_enabled = 0; - ibs_config.dispatched_ops = 1; + ibs_config.dispatched_ops = 0; dir = oprofilefs_mkdir(sb, root, "ibs_fetch"); oprofilefs_create_ulong(sb, dir, "enable", @@ -488,8 +572,9 @@ static int setup_ibs_files(struct super_block *sb, struct dentry *root) &ibs_config.op_enabled); oprofilefs_create_ulong(sb, dir, "max_count", &ibs_config.max_cnt_op); - oprofilefs_create_ulong(sb, dir, "dispatched_ops", - &ibs_config.dispatched_ops); + if (ibs_caps & IBS_CAPS_OPCNT) + oprofilefs_create_ulong(sb, dir, "dispatched_ops", + &ibs_config.dispatched_ops); return 0; } @@ -507,19 +592,6 @@ static void op_amd_exit(void) ibs_exit(); } -#else - -/* no IBS support */ - -static int op_amd_init(struct oprofile_operations *ops) -{ - return 0; -} - -static void op_amd_exit(void) {} - -#endif /* CONFIG_OPROFILE_IBS */ - struct op_x86_model_spec op_amd_spec = { .num_counters = NUM_COUNTERS, .num_controls = NUM_CONTROLS, diff --git a/arch/x86/oprofile/op_model_p4.c b/arch/x86/oprofile/op_model_p4.c index ac6b354..e6a160a 100644 --- a/arch/x86/oprofile/op_model_p4.c +++ b/arch/x86/oprofile/op_model_p4.c @@ -394,12 +394,6 @@ static void p4_fill_in_addresses(struct op_msrs * const msrs) setup_num_counters(); stag = get_stagger(); - /* initialize some registers */ - for (i = 0; i < num_counters; ++i) - msrs->counters[i].addr = 0; - for (i = 0; i < num_controls; ++i) - msrs->controls[i].addr = 0; - /* the counter & cccr registers we pay attention to */ for (i = 0; i < num_counters; ++i) { addr = p4_counters[VIRT_CTR(stag, i)].counter_address; diff --git a/arch/x86/oprofile/op_model_ppro.c b/arch/x86/oprofile/op_model_ppro.c index 8eb0587..5d1727b 100644 --- a/arch/x86/oprofile/op_model_ppro.c +++ b/arch/x86/oprofile/op_model_ppro.c @@ -37,15 +37,11 @@ static void ppro_fill_in_addresses(struct op_msrs * const msrs) for (i = 0; i < num_counters; i++) { if (reserve_perfctr_nmi(MSR_P6_PERFCTR0 + i)) msrs->counters[i].addr = MSR_P6_PERFCTR0 + i; - else - msrs->counters[i].addr = 0; } for (i = 0; i < num_counters; i++) { if (reserve_evntsel_nmi(MSR_P6_EVNTSEL0 + i)) msrs->controls[i].addr = MSR_P6_EVNTSEL0 + i; - else - msrs->controls[i].addr = 0; } } @@ -57,7 +53,7 @@ static void ppro_setup_ctrs(struct op_x86_model_spec const *model, int i; if (!reset_value) { - reset_value = kmalloc(sizeof(reset_value[0]) * num_counters, + reset_value = kzalloc(sizeof(reset_value[0]) * num_counters, GFP_ATOMIC); if (!reset_value) return; @@ -82,9 +78,18 @@ static void ppro_setup_ctrs(struct op_x86_model_spec const *model, /* clear all counters */ for (i = 0; i < num_counters; ++i) { - if (unlikely(!msrs->controls[i].addr)) + if (unlikely(!msrs->controls[i].addr)) { + if (counter_config[i].enabled && !smp_processor_id()) + /* + * counter is reserved, this is on all + * cpus, so report only for cpu #0 + */ + op_x86_warn_reserved(i); continue; + } rdmsrl(msrs->controls[i].addr, val); + if (val & ARCH_PERFMON_EVENTSEL0_ENABLE) + op_x86_warn_in_use(i); val &= model->reserved; wrmsrl(msrs->controls[i].addr, val); } diff --git a/arch/x86/oprofile/op_x86_model.h b/arch/x86/oprofile/op_x86_model.h index 7b8e75d..ff82a75 100644 --- a/arch/x86/oprofile/op_x86_model.h +++ b/arch/x86/oprofile/op_x86_model.h @@ -57,6 +57,26 @@ struct op_x86_model_spec { struct op_counter_config; +static inline void op_x86_warn_in_use(int counter) +{ + /* + * The warning indicates an already running counter. If + * oprofile doesn't collect data, then try using a different + * performance counter on your platform to monitor the desired + * event. Delete counter #%d from the desired event by editing + * the /usr/share/oprofile/%s/<cpu>/events file. If the event + * cannot be monitored by any other counter, contact your + * hardware or BIOS vendor. + */ + pr_warning("oprofile: counter #%d on cpu #%d may already be used\n", + counter, smp_processor_id()); +} + +static inline void op_x86_warn_reserved(int counter) +{ + pr_warning("oprofile: counter #%d is already reserved\n", counter); +} + extern u64 op_x86_get_ctrl(struct op_x86_model_spec const *model, struct op_counter_config *counter_config); extern int op_x86_phys_to_virt(int phys); |