Commit-ID: bf20616f46e536fe8affed6f138db4b3040b55a6 Gitweb: https://git.kernel.org/tip/bf20616f46e536fe8affed6f138db4b3040b55a6 Author: Waiman Long <long...@redhat.com> AuthorDate: Thu, 4 Apr 2019 13:43:18 -0400 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Wed, 10 Apr 2019 10:56:05 +0200
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: Waiman Long <long...@redhat.com> Acked-by: Peter Zijlstra <a.p.zijls...@chello.nl> Acked-by: Davidlohr Bueso <dbu...@suse.de> Cc: Andrew Morton <a...@linux-foundation.org> Cc: Arnd Bergmann <a...@arndb.de> Cc: Borislav Petkov <b...@alien8.de> Cc: Davidlohr Bueso <d...@stgolabs.net> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Paul E. McKenney <paul...@linux.vnet.ibm.com> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Cc: Tim Chen <tim.c.c...@linux.intel.com> Cc: Will Deacon <will.dea...@arm.com> Link: http://lkml.kernel.org/r/20190404174320.22416-10-long...@redhat.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- kernel/locking/lock_events.c | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) diff --git a/kernel/locking/lock_events.c b/kernel/locking/lock_events.c index 71c36d1fb834..fa2c2f951c6b 100644 --- a/kernel/locking/lock_events.c +++ b/kernel/locking/lock_events.c @@ -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,
