s390/stp: Remove udelay from stp_sync_clock()

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When an stp sync check is handled on a system with multiple
cpus each cpu gets a machine check but only the first one
actually handles the sync operation. All other CPUs spin
waiting for the first one to finish with a short udelay().
But udelay can't be used here as the first CPU modifies tod_clock_base
before performing the sync op. During this timeframe
get_tod_clock_monotonic() might return a non-monotonic time.

The time spent waiting should be very short and udelay is a busy loop
anyways, therefore simply remove the udelay.

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

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Sven Schnelle 2025-07-03 13:50:27 +02:00 • committed by Alexander Gordeev

parent 7cf636c99b

commit b367017cda

1 changed files with 1 additions and 1 deletions

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arch/s390/kernel/time.c

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