forked from Minki/linux
[IA64] perfmon: make pfm_sysctl a global, and other cleanup
- make pfm_sysctl a global such that it is possible to enable/disable debug printk in sampling formats using PFM_DEBUG. - remove unused pfm_debug_var variable - fix a bug in pfm_handle_work where an BUG_ON() could be triggered. There is a path where pfm_handle_work() can be called with interrupts enabled, i.e., when TIF_NEED_RESCHED is set. The fix correct the masking and unmasking of interrupts in pfm_handle_work() such that we restore the interrupt mask as it was upon entry. signed-off-by: stephane eranian <eranian@hpl.hp.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
This commit is contained in:
Stephane Eranian
Tony Luck
parent
658b32cad9
commit
4944930ab7
@ -479,14 +479,6 @@ typedef struct {
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#define PFM_CMD_ARG_MANY -1 /* cannot be zero */
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typedef struct {
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int debug; /* turn on/off debugging via syslog */
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int debug_ovfl; /* turn on/off debug printk in overflow handler */
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int fastctxsw; /* turn on/off fast (unsecure) ctxsw */
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int expert_mode; /* turn on/off value checking */
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int debug_pfm_read;
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} pfm_sysctl_t;
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typedef struct {
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unsigned long pfm_spurious_ovfl_intr_count; /* keep track of spurious ovfl interrupts */
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unsigned long pfm_replay_ovfl_intr_count; /* keep track of replayed ovfl interrupts */
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@ -514,8 +506,8 @@ static LIST_HEAD(pfm_buffer_fmt_list);
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static pmu_config_t *pmu_conf;
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/* sysctl() controls */
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static pfm_sysctl_t pfm_sysctl;
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int pfm_debug_var;
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pfm_sysctl_t pfm_sysctl;
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EXPORT_SYMBOL(pfm_sysctl);
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static ctl_table pfm_ctl_table[]={
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{1, "debug", &pfm_sysctl.debug, sizeof(int), 0666, NULL, &proc_dointvec, NULL,},
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@ -1576,7 +1568,7 @@ pfm_read(struct file *filp, char __user *buf, size_t size, loff_t *ppos)
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goto abort_locked;
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}
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DPRINT(("[%d] fd=%d type=%d\n", current->pid, msg->pfm_gen_msg.msg_ctx_fd, msg->pfm_gen_msg.msg_type));
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DPRINT(("fd=%d type=%d\n", msg->pfm_gen_msg.msg_ctx_fd, msg->pfm_gen_msg.msg_type));
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ret = -EFAULT;
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if(copy_to_user(buf, msg, sizeof(pfm_msg_t)) == 0) ret = sizeof(pfm_msg_t);
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@ -3695,8 +3687,6 @@ pfm_debug(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs)
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pfm_sysctl.debug = m == 0 ? 0 : 1;
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pfm_debug_var = pfm_sysctl.debug;
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printk(KERN_INFO "perfmon debugging %s (timing reset)\n", pfm_sysctl.debug ? "on" : "off");
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if (m == 0) {
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@ -4996,13 +4986,21 @@ pfm_context_force_terminate(pfm_context_t *ctx, struct pt_regs *regs)
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}
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static int pfm_ovfl_notify_user(pfm_context_t *ctx, unsigned long ovfl_pmds);
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/*
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* pfm_handle_work() can be called with interrupts enabled
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* (TIF_NEED_RESCHED) or disabled. The down_interruptible
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* call may sleep, therefore we must re-enable interrupts
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* to avoid deadlocks. It is safe to do so because this function
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* is called ONLY when returning to user level (PUStk=1), in which case
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* there is no risk of kernel stack overflow due to deep
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* interrupt nesting.
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*/
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void
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pfm_handle_work(void)
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{
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pfm_context_t *ctx;
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struct pt_regs *regs;
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unsigned long flags;
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unsigned long flags, dummy_flags;
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unsigned long ovfl_regs;
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unsigned int reason;
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int ret;
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@ -5039,18 +5037,15 @@ pfm_handle_work(void)
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//if (CTX_OVFL_NOBLOCK(ctx)) goto skip_blocking;
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if (reason == PFM_TRAP_REASON_RESET) goto skip_blocking;
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/*
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* restore interrupt mask to what it was on entry.
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* Could be enabled/diasbled.
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*/
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UNPROTECT_CTX(ctx, flags);
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/*
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* pfm_handle_work() is currently called with interrupts disabled.
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* The down_interruptible call may sleep, therefore we
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* must re-enable interrupts to avoid deadlocks. It is
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* safe to do so because this function is called ONLY
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* when returning to user level (PUStk=1), in which case
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* there is no risk of kernel stack overflow due to deep
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* interrupt nesting.
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*/
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BUG_ON(flags & IA64_PSR_I);
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/*
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* force interrupt enable because of down_interruptible()
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*/
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local_irq_enable();
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DPRINT(("before block sleeping\n"));
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@ -5064,12 +5059,12 @@ pfm_handle_work(void)
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DPRINT(("after block sleeping ret=%d\n", ret));
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/*
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* disable interrupts to restore state we had upon entering
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* this function
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* lock context and mask interrupts again
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* We save flags into a dummy because we may have
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* altered interrupts mask compared to entry in this
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* function.
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*/
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local_irq_disable();
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PROTECT_CTX(ctx, flags);
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PROTECT_CTX(ctx, dummy_flags);
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/*
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* we need to read the ovfl_regs only after wake-up
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@ -5095,7 +5090,9 @@ skip_blocking:
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ctx->ctx_ovfl_regs[0] = 0UL;
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nothing_to_do:
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/*
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* restore flags as they were upon entry
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*/
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UNPROTECT_CTX(ctx, flags);
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}
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@ -20,24 +20,17 @@ MODULE_AUTHOR("Stephane Eranian <eranian@hpl.hp.com>");
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MODULE_DESCRIPTION("perfmon default sampling format");
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MODULE_LICENSE("GPL");
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MODULE_PARM(debug, "i");
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MODULE_PARM_DESC(debug, "debug");
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MODULE_PARM(debug_ovfl, "i");
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MODULE_PARM_DESC(debug_ovfl, "debug ovfl");
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#define DEFAULT_DEBUG 1
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#ifdef DEFAULT_DEBUG
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#define DPRINT(a) \
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do { \
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if (unlikely(debug >0)) { printk("%s.%d: CPU%d ", __FUNCTION__, __LINE__, smp_processor_id()); printk a; } \
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if (unlikely(pfm_sysctl.debug >0)) { printk("%s.%d: CPU%d ", __FUNCTION__, __LINE__, smp_processor_id()); printk a; } \
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} while (0)
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#define DPRINT_ovfl(a) \
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do { \
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if (unlikely(debug_ovfl >0)) { printk("%s.%d: CPU%d ", __FUNCTION__, __LINE__, smp_processor_id()); printk a; } \
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if (unlikely(pfm_sysctl.debug > 0 && pfm_sysctl.debug_ovfl >0)) { printk("%s.%d: CPU%d ", __FUNCTION__, __LINE__, smp_processor_id()); printk a; } \
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} while (0)
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#else
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@ -45,8 +38,6 @@ MODULE_PARM_DESC(debug_ovfl, "debug ovfl");
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#define DPRINT_ovfl(a)
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#endif
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static int debug, debug_ovfl;
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static int
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default_validate(struct task_struct *task, unsigned int flags, int cpu, void *data)
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{
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@ -254,6 +254,18 @@ extern int pfm_mod_write_dbrs(struct task_struct *task, void *req, unsigned int
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#define PFM_CPUINFO_DCR_PP 0x2 /* if set the system wide session has started */
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#define PFM_CPUINFO_EXCL_IDLE 0x4 /* the system wide session excludes the idle task */
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/*
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* sysctl control structure. visible to sampling formats
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*/
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typedef struct {
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int debug; /* turn on/off debugging via syslog */
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int debug_ovfl; /* turn on/off debug printk in overflow handler */
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int fastctxsw; /* turn on/off fast (unsecure) ctxsw */
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int expert_mode; /* turn on/off value checking */
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} pfm_sysctl_t;
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extern pfm_sysctl_t pfm_sysctl;
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#endif /* __KERNEL__ */
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#endif /* _ASM_IA64_PERFMON_H */
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