diff mbox series

[v3,2/9] powerpc/pseries: Do not save the previous DTL mask value

Message ID 3267de021d512e97773ad8889e40d2a21c1189cb.1562171646.git.naveen.n.rao@linux.vnet.ibm.com (mailing list archive)
State Accepted
Commit 5b3306f084590b298c1fe1b02aca5bac1abbbc34
Headers show
Series Provide vcpu dispatch statistics | expand

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Context Check Description
snowpatch_ozlabs/apply_patch success Successfully applied on branch next (f531d5e8f55b3767217b5d1be0ce1f1acd10167c)
snowpatch_ozlabs/checkpatch success total: 0 errors, 0 warnings, 0 checks, 22 lines checked

Commit Message

Naveen N. Rao July 3, 2019, 5:03 p.m. UTC 
When CONFIG_VIRT_CPU_ACCOUNTING_NATIVE is enabled, we always initialize
DTL enable mask to DTL_LOG_PREEMPT (0x2). There are no other places
where the mask is changed. As such, when reading the DTL log buffer
through debugfs, there is no need to save and restore the previous mask
value.

We don't need to save and restore the earlier mask value if
CONFIG_VIRT_CPU_ACCOUNTING_NATIVE is not enabled. So, remove the field
from the structure as well.

Acked-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
---
 arch/powerpc/platforms/pseries/dtl.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/arch/powerpc/platforms/pseries/dtl.c b/arch/powerpc/platforms/pseries/dtl.c
index 337378f3d1fd..a88176afba32 100644
--- a/arch/powerpc/platforms/pseries/dtl.c
+++ b/arch/powerpc/platforms/pseries/dtl.c
@@ -42,7 +42,6 @@  struct dtl_ring {
 	struct dtl_entry *write_ptr;
 	struct dtl_entry *buf;
 	struct dtl_entry *buf_end;
-	u8	saved_dtl_mask;
 };
 
 static DEFINE_PER_CPU(struct dtl_ring, dtl_rings);
@@ -92,7 +91,6 @@  static int dtl_start(struct dtl *dtl)
 	dtlr->write_ptr = dtl->buf;
 
 	/* enable event logging */
-	dtlr->saved_dtl_mask = lppaca_of(dtl->cpu).dtl_enable_mask;
 	lppaca_of(dtl->cpu).dtl_enable_mask |= dtl_event_mask;
 
 	dtl_consumer = consume_dtle;
@@ -110,7 +108,7 @@  static void dtl_stop(struct dtl *dtl)
 	dtlr->buf = NULL;
 
 	/* restore dtl_enable_mask */
-	lppaca_of(dtl->cpu).dtl_enable_mask = dtlr->saved_dtl_mask;
+	lppaca_of(dtl->cpu).dtl_enable_mask = DTL_LOG_PREEMPT;
 
 	if (atomic_dec_and_test(&dtl_count))
 		dtl_consumer = NULL;