cf9efce0ce
Currently, when CONFIG_VIRT_CPU_ACCOUNTING is enabled, we use the PURR register for measuring the user and system time used by processes, as well as other related times such as hardirq and softirq times. This turns out to be quite confusing for users because it means that a program will often be measured as taking less time when run on a multi-threaded processor (SMT2 or SMT4 mode) than it does when run on a single-threaded processor (ST mode), even though the program takes longer to finish. The discrepancy is accounted for as stolen time, which is also confusing, particularly when there are no other partitions running. This changes the accounting to use the timebase instead, meaning that the reported user and system times are the actual number of real-time seconds that the program was executing on the processor thread, regardless of which SMT mode the processor is in. Thus a program will generally show greater user and system times when run on a multi-threaded processor than on a single-threaded processor. On pSeries systems on POWER5 or later processors, we measure the stolen time (time when this partition wasn't running) using the hypervisor dispatch trace log. We check for new entries in the log on every entry from user mode and on every transition from kernel process context to soft or hard IRQ context (i.e. when account_system_vtime() gets called). So that we can correctly distinguish time stolen from user time and time stolen from system time, without having to check the log on every exit to user mode, we store separate timestamps for exit to user mode and entry from user mode. On systems that have a SPURR (POWER6 and POWER7), we read the SPURR in account_system_vtime() (as before), and then apportion the SPURR ticks since the last time we read it between scaled user time and scaled system time according to the relative proportions of user time and system time over the same interval. This avoids having to read the SPURR on every kernel entry and exit. On systems that have PURR but not SPURR (i.e., POWER5), we do the same using the PURR rather than the SPURR. This disables the DTL user interface in /sys/debug/kernel/powerpc/dtl for now since it conflicts with the use of the dispatch trace log by the time accounting code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
169 lines
5.5 KiB
C
169 lines
5.5 KiB
C
/*
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* This control block defines the PACA which defines the processor
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* specific data for each logical processor on the system.
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* There are some pointers defined that are utilized by PLIC.
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*
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* C 2001 PPC 64 Team, IBM Corp
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#ifndef _ASM_POWERPC_PACA_H
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#define _ASM_POWERPC_PACA_H
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#ifdef __KERNEL__
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#ifdef CONFIG_PPC64
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#include <linux/init.h>
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#include <asm/types.h>
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#include <asm/lppaca.h>
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#include <asm/mmu.h>
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#include <asm/page.h>
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#include <asm/exception-64e.h>
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#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
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#include <asm/kvm_book3s_asm.h>
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#endif
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register struct paca_struct *local_paca asm("r13");
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#if defined(CONFIG_DEBUG_PREEMPT) && defined(CONFIG_SMP)
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extern unsigned int debug_smp_processor_id(void); /* from linux/smp.h */
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/*
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* Add standard checks that preemption cannot occur when using get_paca():
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* otherwise the paca_struct it points to may be the wrong one just after.
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*/
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#define get_paca() ((void) debug_smp_processor_id(), local_paca)
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#else
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#define get_paca() local_paca
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#endif
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#define get_lppaca() (get_paca()->lppaca_ptr)
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#define get_slb_shadow() (get_paca()->slb_shadow_ptr)
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struct task_struct;
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/*
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* Defines the layout of the paca.
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*
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* This structure is not directly accessed by firmware or the service
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* processor.
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*/
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struct paca_struct {
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#ifdef CONFIG_PPC_BOOK3S
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/*
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* Because hw_cpu_id, unlike other paca fields, is accessed
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* routinely from other CPUs (from the IRQ code), we stick to
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* read-only (after boot) fields in the first cacheline to
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* avoid cacheline bouncing.
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*/
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struct lppaca *lppaca_ptr; /* Pointer to LpPaca for PLIC */
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#endif /* CONFIG_PPC_BOOK3S */
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/*
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* MAGIC: the spinlock functions in arch/powerpc/lib/locks.c
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* load lock_token and paca_index with a single lwz
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* instruction. They must travel together and be properly
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* aligned.
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*/
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u16 lock_token; /* Constant 0x8000, used in locks */
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u16 paca_index; /* Logical processor number */
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u64 kernel_toc; /* Kernel TOC address */
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u64 kernelbase; /* Base address of kernel */
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u64 kernel_msr; /* MSR while running in kernel */
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#ifdef CONFIG_PPC_STD_MMU_64
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u64 stab_real; /* Absolute address of segment table */
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u64 stab_addr; /* Virtual address of segment table */
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#endif /* CONFIG_PPC_STD_MMU_64 */
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void *emergency_sp; /* pointer to emergency stack */
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u64 data_offset; /* per cpu data offset */
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s16 hw_cpu_id; /* Physical processor number */
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u8 cpu_start; /* At startup, processor spins until */
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/* this becomes non-zero. */
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u8 kexec_state; /* set when kexec down has irqs off */
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#ifdef CONFIG_PPC_STD_MMU_64
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struct slb_shadow *slb_shadow_ptr;
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struct dtl_entry *dispatch_log;
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struct dtl_entry *dispatch_log_end;
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/*
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* Now, starting in cacheline 2, the exception save areas
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*/
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/* used for most interrupts/exceptions */
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u64 exgen[10] __attribute__((aligned(0x80)));
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u64 exmc[10]; /* used for machine checks */
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u64 exslb[10]; /* used for SLB/segment table misses
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* on the linear mapping */
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/* SLB related definitions */
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u16 vmalloc_sllp;
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u16 slb_cache_ptr;
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u16 slb_cache[SLB_CACHE_ENTRIES];
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#endif /* CONFIG_PPC_STD_MMU_64 */
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#ifdef CONFIG_PPC_BOOK3E
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pgd_t *pgd; /* Current PGD */
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pgd_t *kernel_pgd; /* Kernel PGD */
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u64 exgen[8] __attribute__((aligned(0x80)));
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u64 extlb[EX_TLB_SIZE*3] __attribute__((aligned(0x80)));
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u64 exmc[8]; /* used for machine checks */
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u64 excrit[8]; /* used for crit interrupts */
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u64 exdbg[8]; /* used for debug interrupts */
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/* Kernel stack pointers for use by special exceptions */
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void *mc_kstack;
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void *crit_kstack;
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void *dbg_kstack;
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#endif /* CONFIG_PPC_BOOK3E */
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mm_context_t context;
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/*
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* then miscellaneous read-write fields
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*/
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struct task_struct *__current; /* Pointer to current */
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u64 kstack; /* Saved Kernel stack addr */
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u64 stab_rr; /* stab/slb round-robin counter */
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u64 saved_r1; /* r1 save for RTAS calls */
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u64 saved_msr; /* MSR saved here by enter_rtas */
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u16 trap_save; /* Used when bad stack is encountered */
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u8 soft_enabled; /* irq soft-enable flag */
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u8 hard_enabled; /* set if irqs are enabled in MSR */
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u8 io_sync; /* writel() needs spin_unlock sync */
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u8 perf_event_pending; /* PM interrupt while soft-disabled */
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/* Stuff for accurate time accounting */
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u64 user_time; /* accumulated usermode TB ticks */
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u64 system_time; /* accumulated system TB ticks */
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u64 user_time_scaled; /* accumulated usermode SPURR ticks */
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u64 starttime; /* TB value snapshot */
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u64 starttime_user; /* TB value on exit to usermode */
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u64 startspurr; /* SPURR value snapshot */
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u64 utime_sspurr; /* ->user_time when ->startspurr set */
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u64 stolen_time; /* TB ticks taken by hypervisor */
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u64 dtl_ridx; /* read index in dispatch log */
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struct dtl_entry *dtl_curr; /* pointer corresponding to dtl_ridx */
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#ifdef CONFIG_KVM_BOOK3S_HANDLER
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/* We use this to store guest state in */
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struct kvmppc_book3s_shadow_vcpu shadow_vcpu;
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#endif
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};
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extern struct paca_struct *paca;
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extern __initdata struct paca_struct boot_paca;
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extern void initialise_paca(struct paca_struct *new_paca, int cpu);
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extern void setup_paca(struct paca_struct *new_paca);
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extern void allocate_pacas(void);
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extern void free_unused_pacas(void);
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#else /* CONFIG_PPC64 */
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static inline void allocate_pacas(void) { };
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static inline void free_unused_pacas(void) { };
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#endif /* CONFIG_PPC64 */
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#endif /* __KERNEL__ */
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#endif /* _ASM_POWERPC_PACA_H */
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