2020-01-18 17:14:32

by Mateusz Nosek

Subject: [PATCH] arch/x86/kernel/tsc_sync.c: Clean up code by removing unused assignment

From: Mateusz Nosek <[email protected]>

Previously the assignment to local variable 'now' took place before the for
loop. The loop is unconditional so it will be entered at least once. The
variable 'now' is reassigned in the loop and is not used before reassigning.
Therefore the assignment before the loop is unnecessary and can be removed.

Signed-off-by: Mateusz Nosek <[email protected]>
---
arch/x86/kernel/tsc_sync.c | 1 -
1 file changed, 1 deletion(-)

diff --git a/arch/x86/kernel/tsc_sync.c b/arch/x86/kernel/tsc_sync.c
index b8acf639abd1..32a818764e03 100644
--- a/arch/x86/kernel/tsc_sync.c
+++ b/arch/x86/kernel/tsc_sync.c
@@ -233,7 +233,6 @@ static cycles_t check_tsc_warp(unsigned int timeout)
* The measurement runs for 'timeout' msecs:
*/
end = start + (cycles_t) tsc_khz * timeout;
- now = start;

for (i = 0; ; i++) {
/*
--
2.17.1

2020-01-22 13:04:30

by tip-bot2 for Jacob Pan

Subject: [tip: x86/cleanups] x86/tsc: Remove redundant assignment

The following commit has been merged into the x86/cleanups branch of tip:

Commit-ID: 4144fddbd3932b59370e6e279002991c3e2b2fc6
Gitweb: https://git.kernel.org/tip/4144fddbd3932b59370e6e279002991c3e2b2fc6
Author: Mateusz Nosek <[email protected]>
AuthorDate: Sat, 18 Jan 2020 18:11:43 +01:00
Committer: Borislav Petkov <[email protected]>
CommitterDate: Wed, 22 Jan 2020 13:52:42 +01:00

x86/tsc: Remove redundant assignment

Previously, the assignment to the local variable 'now' took place
before the for loop. The loop is unconditional so it will be entered
at least once. The variable 'now' is reassigned in the loop and is not
used before reassigning. Therefore, the assignment before the loop is
unnecessary and can be removed.

No code changed:

# arch/x86/kernel/tsc_sync.o:

text data bss dec hex filename
3569 198 44 3811 ee3 tsc_sync.o.before
3569 198 44 3811 ee3 tsc_sync.o.after

md5:
36216de29b208edbcd34fed9fe7f7b69 tsc_sync.o.before.asm
36216de29b208edbcd34fed9fe7f7b69 tsc_sync.o.after.asm

[ bp: Massage commit message. ]

Signed-off-by: Mateusz Nosek <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
---
arch/x86/kernel/tsc_sync.c | 1 -
1 file changed, 1 deletion(-)

diff --git a/arch/x86/kernel/tsc_sync.c b/arch/x86/kernel/tsc_sync.c
index b8acf63..32a8187 100644
--- a/arch/x86/kernel/tsc_sync.c
+++ b/arch/x86/kernel/tsc_sync.c
@@ -233,7 +233,6 @@ static cycles_t check_tsc_warp(unsigned int timeout)
* The measurement runs for 'timeout' msecs:
*/
end = start + (cycles_t) tsc_khz * timeout;
- now = start;

for (i = 0; ; i++) {
/*