[PATCH v2 25/25] timekeeping: Merge timekeeping_update_staged() and timekeeping_update()

From: Anna-Maria Behnsen
Date: Wed Oct 09 2024 - 04:34:46 EST


From: Anna-Maria Behnsen <anna-maria@xxxxxxxxxxxxx>

timekeeping_update_staged() is the only call site of timekeeping_update().

Merge those functions. No functional change.

Signed-off-by: Anna-Maria Behnsen <anna-maria@xxxxxxxxxxxxx>
---
kernel/time/timekeeping.c | 31 ++++++++++++++-----------------
1 file changed, 14 insertions(+), 17 deletions(-)

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 67d7be2e02fb..d07eb1946ff1 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -529,7 +529,7 @@ EXPORT_SYMBOL_GPL(ktime_get_raw_fast_ns);
* timekeeping_inject_sleeptime64()
* __timekeeping_inject_sleeptime(tk, delta);
* timestamp();
- * timekeeping_update(tkd, tk, TK_CLEAR_NTP...);
+ * timekeeping_update_staged(tkd, TK_CLEAR_NTP...);
*
* (2) On 32-bit systems, the 64-bit boot offset (tk->offs_boot) may be
* partially updated. Since the tk->offs_boot update is a rare event, this
@@ -775,10 +775,21 @@ static void timekeeping_restore_shadow(struct tk_data *tkd)
memcpy(&tkd->shadow_timekeeper, &tkd->timekeeper, sizeof(tkd->timekeeper));
}

-static void timekeeping_update(struct tk_data *tkd, struct timekeeper *tk, unsigned int action)
+static void timekeeping_update_staged(struct tk_data *tkd, unsigned int action)
{
+ struct timekeeper *tk = &tk_core.shadow_timekeeper;
+
lockdep_assert_held(&tkd->lock);

+ /*
+ * Block out readers before running the updates below because that
+ * updates VDSO and other time related infrastructure. Not blocking
+ * the readers might let a reader see time going backwards when
+ * reading from the VDSO after the VDSO update and then reading in
+ * the kernel from the timekeeper before that got updated.
+ */
+ write_seqcount_begin(&tkd->seq);
+
if (action & TK_CLEAR_NTP) {
tk->ntp_error = 0;
ntp_clear();
@@ -796,20 +807,6 @@ static void timekeeping_update(struct tk_data *tkd, struct timekeeper *tk, unsig

if (action & TK_CLOCK_WAS_SET)
tk->clock_was_set_seq++;
-}
-
-static void timekeeping_update_staged(struct tk_data *tkd, unsigned int action)
-{
- /*
- * Block out readers before invoking timekeeping_update() because
- * that updates VDSO and other time related infrastructure. Not
- * blocking the readers might let a reader see time going backwards
- * when reading from the VDSO after the VDSO update and then
- * reading in the kernel from the timekeeper before that got updated.
- */
- write_seqcount_begin(&tkd->seq);
-
- timekeeping_update(tkd, &tkd->shadow_timekeeper, action);

/*
* Update the real timekeeper.
@@ -819,7 +816,7 @@ static void timekeeping_update_staged(struct tk_data *tkd, unsigned int action)
* the cacheline optimized data layout of the timekeeper and requires
* another indirection.
*/
- memcpy(&tkd->timekeeper, &tkd->shadow_timekeeper, sizeof(tkd->shadow_timekeeper));
+ memcpy(&tkd->timekeeper, tk, sizeof(*tk));
write_seqcount_end(&tkd->seq);
}


--
2.39.5