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

[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
......@@ -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.
*/
BUG_ON(flags & IA64_PSR_I);
/*
* force interrupt enable because of down_interruptible()
*/
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);
}
......
......@@ -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)
{
......
......@@ -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 */
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