Thank you Maciej for the review!
On 03/06/2015 04:47 AM, Maciej W. Rozycki wrote:
On Wed, 4 Mar 2015, Deng-Cheng Zhu wrote:
Use sb1250 hpt for sched_clock source. This implementation will give high
resolution cputime accounting.
Signed-off-by: Deng-Cheng Zhu <dengcheng.zhu@xxxxxxxxxx>
---
arch/mips/kernel/csrc-sb1250.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/arch/mips/kernel/csrc-sb1250.c b/arch/mips/kernel/csrc-sb1250.c
index df84836..6546fff 100644
--- a/arch/mips/kernel/csrc-sb1250.c
+++ b/arch/mips/kernel/csrc-sb1250.c
@@ -12,6 +12,7 @@
* GNU General Public License for more details.
*/
#include <linux/clocksource.h>
+#include <linux/sched_clock.h>
#include <asm/addrspace.h>
#include <asm/io.h>
@@ -46,6 +47,11 @@ struct clocksource bcm1250_clocksource = {
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
+static u64 notrace sb1250_read_sched_clock(void)
+{
+ return sb1250_hpt_read(NULL);
+}
+
I think you're abusing the API of `sb1250_hpt_read' here, by relying on
the implementation not using its `cs' argument.
I think it would make sense to reverse the implementation, by calling
`sb1250_read_sched_clock' from `sb1250_hpt_read' instead. Or perhaps
better yet use a static inline helper for both, so as to avoid the extra
tail call and the associated performance hit.
Maciej
Good point. Will do in v2.
Deng-Cheng
