android-5.4/FROMLIST-vsprintf-Inline-call-to-ptr_to_hashval.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: "Joel Fernandes (Google)" <joel@joelfernandes.org>
Date: Mon, 18 Nov 2019 14:08:03 -0500
Subject: FROMLIST: vsprintf: Inline call to ptr_to_hashval

There is concern that ptr_to_hashval not being inlined can cause performance
issues (unlike before where it was a static branch) with trace_printk being a
hot path for it. Just create an inline version called __ptr_to_hashval(), and
have the actual ptr_to_hashval() call it.

Bug: 145972256

Link: http://lore.kernel.org/r/20191113153816.14b95acd@gandalf.local.home
Link: lore.kernel.org/r/20191114164622.GC233237@google.com
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Change-Id: Ie7133b9f32a8185e244db2634b028b316a3d7ea1
Signed-off-by: Joel Fernandes <joel@joelfernandes.org>
Signed-off-by: Joel Fernandes <joelaf@google.com>
(cherry picked from commit 0f2b4ea6e2356687ce78ff23b8556d2138b6fe28)
---
 lib/vsprintf.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 465c5758d222..294468db3fb3 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -739,7 +739,7 @@ static int __init initialize_ptr_random(void)
 }
 early_initcall(initialize_ptr_random);
  
-int ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
+static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
 {
 	unsigned long hashval;
 
@@ -760,6 +760,11 @@ int ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
 	return 0;
 }
 
+int ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
+{
+	return __ptr_to_hashval(ptr, hashval_out);
+}
+
 /* Maps a pointer to a 32 bit unique identifier. */
 static char *ptr_to_id(char *buf, char *end, const void *ptr,
 		       struct printf_spec spec)
@@ -774,7 +779,7 @@ static char *ptr_to_id(char *buf, char *end, const void *ptr,
 		return pointer_string(buf, end, (const void *)hashval, spec);
 	}
 
-	ret = ptr_to_hashval(ptr, &hashval);
+	ret = __ptr_to_hashval(ptr, &hashval);
 	if (ret) {
 		spec.field_width = 2 * sizeof(ptr);
 		/* string length must be less than default_width */