The following commit has been merged into the timers/vdso branch of tip:
Commit-ID: 97a5a90ca234eaa3de8a6aa44d43de2827393019
Gitweb: https://git.kernel.org/tip/97a5a90ca234eaa3de8a6aa44d43de2827393019
Author: Anna-Maria Behnsen <anna-maria@xxxxxxxxxxxxx>
AuthorDate: Mon, 03 Mar 2025 12:11:20 +01:00
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Sat, 08 Mar 2025 14:37:41 +01:00
vdso: Move architecture related data before basetime data
Architecture related vdso data is required in the fast path when reading
CLOCK_MONOTONIC or CLOCK_REALTIME. At the moment, this information is
located at the end of the vdso_time_data structure, which is a suboptimal
cache layout.
Move the architecture specific VDSO data right before the basetime
information, which is always required. This change does not have an impact
on architectures with CONFIG_ARCH_HAS_VDSO_DATA=n. Architectures, which
have it enabled, gain a better cache layout.
Signed-off-by: Anna-Maria Behnsen <anna-maria@xxxxxxxxxxxxx>
Signed-off-by: Nam Cao <namcao@xxxxxxxxxxxxx>
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@xxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/all/20250303-vdso-clock-v1-18-c1b5c69a166f@xxxxxxxxxxxxx
---
include/vdso/datapage.h | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/include/vdso/datapage.h b/include/vdso/datapage.h
index 1df22e8..bcd19c2 100644
--- a/include/vdso/datapage.h
+++ b/include/vdso/datapage.h
@@ -70,6 +70,8 @@ struct vdso_timestamp {
/**
* struct vdso_time_data - vdso datapage representation
+ * @arch_data: architecture specific data (optional, defaults
+ * to an empty struct)
* @seq: timebase sequence counter
* @clock_mode: clock mode
* @cycle_last: timebase at clocksource init
@@ -83,8 +85,6 @@ struct vdso_timestamp {
* @tz_dsttime: type of DST correction
* @hrtimer_res: hrtimer resolution
* @__unused: unused
- * @arch_data: architecture specific data (optional, defaults
- * to an empty struct)
*
* vdso_time_data will be accessed by 64 bit and compat code at the same time
* so we should be careful before modifying this structure.
@@ -105,6 +105,8 @@ struct vdso_timestamp {
* offset must be zero.
*/
struct vdso_time_data {
+ struct arch_vdso_time_data arch_data;
+
u32 seq;
s32 clock_mode;
@@ -125,8 +127,6 @@ struct vdso_time_data {
s32 tz_dsttime;
u32 hrtimer_res;
u32 __unused;
-
- struct arch_vdso_time_data arch_data;
} ____cacheline_aligned;
#define vdso_clock vdso_time_data
|