Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 4944930a authored by Stephane Eranian's avatar Stephane Eranian Committed by Tony Luck
Browse files

[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: default avatarstephane eranian <eranian@hpl.hp.com>
Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
parent 658b32ca

arch/ia64/kernel/perfmon.c

+28 −31
Original line number Diff line number Diff line
@@ -479,14 +479,6 @@ typedef struct { 


#define PFM_CMD_ARG_MANY	-1 /* cannot be zero */



typedef struct {

	int	debug;		/* turn on/off debugging via syslog */

	int	debug_ovfl;	/* turn on/off debug printk in overflow handler */

	int	fastctxsw;	/* turn on/off fast (unsecure) ctxsw */

	int	expert_mode;	/* turn on/off value checking */

	int 	debug_pfm_read;

} pfm_sysctl_t;



typedef struct {

	unsigned long pfm_spurious_ovfl_intr_count;	/* keep track of spurious ovfl interrupts */

	unsigned long pfm_replay_ovfl_intr_count;	/* keep track of replayed ovfl interrupts */
@@ -514,8 +506,8 @@ static LIST_HEAD(pfm_buffer_fmt_list); 
static pmu_config_t		*pmu_conf;



/* sysctl() controls */

static pfm_sysctl_t pfm_sysctl;

int pfm_debug_var;

pfm_sysctl_t pfm_sysctl;

EXPORT_SYMBOL(pfm_sysctl);



static ctl_table pfm_ctl_table[]={

	{1, "debug", &pfm_sysctl.debug, sizeof(int), 0666, NULL, &proc_dointvec, NULL,},
@@ -1576,7 +1568,7 @@ pfm_read(struct file *filp, char __user *buf, size_t size, loff_t *ppos) 
		goto abort_locked;

	}



	DPRINT(("[%d] fd=%d type=%d\n", current->pid, msg->pfm_gen_msg.msg_ctx_fd, msg->pfm_gen_msg.msg_type));

	DPRINT(("fd=%d type=%d\n", msg->pfm_gen_msg.msg_ctx_fd, msg->pfm_gen_msg.msg_type));



	ret = -EFAULT;

  	if(copy_to_user(buf, msg, sizeof(pfm_msg_t)) == 0) ret = sizeof(pfm_msg_t);
@@ -3695,8 +3687,6 @@ pfm_debug(pfm_context_t *ctx, void *arg, int count, struct pt_regs *regs) 


	pfm_sysctl.debug = m == 0 ? 0 : 1;



	pfm_debug_var = pfm_sysctl.debug;



	printk(KERN_INFO "perfmon debugging %s (timing reset)\n", pfm_sysctl.debug ? "on" : "off");



	if (m == 0) {
@@ -4996,13 +4986,21 @@ pfm_context_force_terminate(pfm_context_t *ctx, struct pt_regs *regs) 
}



static int pfm_ovfl_notify_user(pfm_context_t *ctx, unsigned long ovfl_pmds);



 /*

  * pfm_handle_work() can be called with interrupts enabled

  * (TIF_NEED_RESCHED) or disabled. The down_interruptible

  * call may sleep, therefore we must re-enable interrupts

  * to avoid deadlocks. It is safe to do so because this function

  * is called ONLY when returning to user level (PUStk=1), in which case

  * there is no risk of kernel stack overflow due to deep

  * interrupt nesting.

  */

void

pfm_handle_work(void)

{

	pfm_context_t *ctx;

	struct pt_regs *regs;

	unsigned long flags;

	unsigned long flags, dummy_flags;

	unsigned long ovfl_regs;

	unsigned int reason;

	int ret;
@@ -5039,18 +5037,15 @@ pfm_handle_work(void) 
	//if (CTX_OVFL_NOBLOCK(ctx)) goto skip_blocking;

	if (reason == PFM_TRAP_REASON_RESET) goto skip_blocking;



	/*

	 * restore interrupt mask to what it was on entry.

	 * Could be enabled/diasbled.

	 */

	UNPROTECT_CTX(ctx, flags);



	/*

	  * pfm_handle_work() is currently called with interrupts disabled.

	  * The down_interruptible call may sleep, therefore we

	  * must re-enable interrupts to avoid deadlocks. It is

	  * safe to do so because this function is called ONLY

	  * when returning to user level (PUStk=1), in which case

	  * there is no risk of kernel stack overflow due to deep

	  * interrupt nesting.

	 * force interrupt enable because of down_interruptible()

	 */

	BUG_ON(flags & IA64_PSR_I);

	local_irq_enable();



	DPRINT(("before block sleeping\n"));
@@ -5064,12 +5059,12 @@ pfm_handle_work(void) 
	DPRINT(("after block sleeping ret=%d\n", ret));



	/*

	 * disable interrupts to restore state we had upon entering

	 * this function

	 * lock context and mask interrupts again

	 * We save flags into a dummy because we may have

	 * altered interrupts mask compared to entry in this

	 * function.

	 */

	local_irq_disable();



	PROTECT_CTX(ctx, flags);

	PROTECT_CTX(ctx, dummy_flags);



	/*

	 * we need to read the ovfl_regs only after wake-up
@@ -5095,7 +5090,9 @@ pfm_handle_work(void) 
	ctx->ctx_ovfl_regs[0] = 0UL;



nothing_to_do:



	/*

	 * restore flags as they were upon entry

	 */

	UNPROTECT_CTX(ctx, flags);

}

arch/ia64/kernel/perfmon_default_smpl.c

+2 −11
Original line number Diff line number Diff line
@@ -20,24 +20,17 @@ MODULE_AUTHOR("Stephane Eranian <eranian@hpl.hp.com>"); 
MODULE_DESCRIPTION("perfmon default sampling format");

MODULE_LICENSE("GPL");



MODULE_PARM(debug, "i");

MODULE_PARM_DESC(debug, "debug");



MODULE_PARM(debug_ovfl, "i");

MODULE_PARM_DESC(debug_ovfl, "debug ovfl");





#define DEFAULT_DEBUG 1



#ifdef DEFAULT_DEBUG

#define DPRINT(a) \

	do { \

		if (unlikely(debug >0)) { printk("%s.%d: CPU%d ", __FUNCTION__, __LINE__, smp_processor_id()); printk a; } \

		if (unlikely(pfm_sysctl.debug >0)) { printk("%s.%d: CPU%d ", __FUNCTION__, __LINE__, smp_processor_id()); printk a; } \

	} while (0)



#define DPRINT_ovfl(a) \

	do { \

		if (unlikely(debug_ovfl >0)) { printk("%s.%d: CPU%d ", __FUNCTION__, __LINE__, smp_processor_id()); printk a; } \

		if (unlikely(pfm_sysctl.debug > 0 && pfm_sysctl.debug_ovfl >0)) { printk("%s.%d: CPU%d ", __FUNCTION__, __LINE__, smp_processor_id()); printk a; } \

	} while (0)



#else
@@ -45,8 +38,6 @@ MODULE_PARM_DESC(debug_ovfl, "debug ovfl"); 
#define DPRINT_ovfl(a)

#endif



static int debug, debug_ovfl;



static int

default_validate(struct task_struct *task, unsigned int flags, int cpu, void *data)

{

include/asm-ia64/perfmon.h

+12 −0
Original line number Diff line number Diff line
@@ -254,6 +254,18 @@ extern int pfm_mod_write_dbrs(struct task_struct *task, void *req, unsigned int 
#define PFM_CPUINFO_DCR_PP	0x2	/* if set the system wide session has started */

#define PFM_CPUINFO_EXCL_IDLE	0x4	/* the system wide session excludes the idle task */



/*

 * sysctl control structure. visible to sampling formats

 */

typedef struct {

	int	debug;		/* turn on/off debugging via syslog */

	int	debug_ovfl;	/* turn on/off debug printk in overflow handler */

	int	fastctxsw;	/* turn on/off fast (unsecure) ctxsw */

	int	expert_mode;	/* turn on/off value checking */

} pfm_sysctl_t;

extern pfm_sysctl_t pfm_sysctl;





#endif /* __KERNEL__ */



#endif /* _ASM_IA64_PERFMON_H */