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Commit bf20616f authored by Waiman Long's avatar Waiman Long Committed by Ingo Molnar
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locking/lock_events: Don't show pvqspinlock events on bare metal


On bare metal, the pvqspinlock event counts will always be 0. So there
is no point in showing their corresponding debugfs files. So they are
skipped in this case.

Signed-off-by: default avatarWaiman Long <longman@redhat.com>
Acked-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: default avatarDavidlohr Bueso <dbueso@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/20190404174320.22416-10-longman@redhat.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent fb346fd9
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......@@ -115,6 +115,29 @@ static const struct file_operations fops_lockevent = {
.llseek = default_llseek,
};
#ifdef CONFIG_PARAVIRT_SPINLOCKS
#include <asm/paravirt.h>
static bool __init skip_lockevent(const char *name)
{
static int pv_on __initdata = -1;
if (pv_on < 0)
pv_on = !pv_is_native_spin_unlock();
/*
* Skip PV qspinlock events on bare metal.
*/
if (!pv_on && !memcmp(name, "pv_", 3))
return true;
return false;
}
#else
static inline bool skip_lockevent(const char *name)
{
return false;
}
#endif
/*
* Initialize debugfs for the locking event counts.
*/
......@@ -133,10 +156,13 @@ static int __init init_lockevent_counts(void)
* root is allowed to do the read/write to limit impact to system
* performance.
*/
for (i = 0; i < lockevent_num; i++)
for (i = 0; i < lockevent_num; i++) {
if (skip_lockevent(lockevent_names[i]))
continue;
if (!debugfs_create_file(lockevent_names[i], 0400, d_counts,
(void *)(long)i, &fops_lockevent))
goto fail_undo;
}
if (!debugfs_create_file(lockevent_names[LOCKEVENT_reset_cnts], 0200,
d_counts, (void *)(long)LOCKEVENT_reset_cnts,
......
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