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| author | Konstantin Belousov <kib@FreeBSD.org> | 2017-12-19 10:05:45 +0000 |
|---|---|---|
| committer | Konstantin Belousov <kib@FreeBSD.org> | 2017-12-19 10:05:45 +0000 |
| commit | 6f697994fd36703d412a100c6e1b626fbf194cd4 (patch) | |
| tree | cffbc8c23eb005293881033d4f8d3d9297c2afdb /sys/kern | |
| parent | 30d4f9e8883099cbdbcb732b68372b7c2e0ec979 (diff) | |
| download | src-6f697994fd36703d412a100c6e1b626fbf194cd4.tar.gz src-6f697994fd36703d412a100c6e1b626fbf194cd4.zip | |
Use atomic_load(9) to read ppsinfo sequence numbers.
In this case volatile qualifiers enusre that a compiler does not
optimize the accesses out.
Reviewed by: alc, jhb
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D13534
Notes
Notes:
svn path=/head/; revision=326973
Diffstat (limited to 'sys/kern')
| -rw-r--r-- | sys/kern/kern_tc.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/sys/kern/kern_tc.c b/sys/kern/kern_tc.c index 377a8b55359a..d291bc78fad3 100644 --- a/sys/kern/kern_tc.c +++ b/sys/kern/kern_tc.c @@ -1601,10 +1601,10 @@ pps_fetch(struct pps_fetch_args *fapi, struct pps_state *pps) tv.tv_usec = fapi->timeout.tv_nsec / 1000; timo = tvtohz(&tv); } - aseq = pps->ppsinfo.assert_sequence; - cseq = pps->ppsinfo.clear_sequence; - while (aseq == pps->ppsinfo.assert_sequence && - cseq == pps->ppsinfo.clear_sequence) { + aseq = atomic_load_int(&pps->ppsinfo.assert_sequence); + cseq = atomic_load_int(&pps->ppsinfo.clear_sequence); + while (aseq == atomic_load_int(&pps->ppsinfo.assert_sequence) && + cseq == atomic_load_int(&pps->ppsinfo.clear_sequence)) { if (abi_aware(pps, 1) && pps->driver_mtx != NULL) { if (pps->flags & PPSFLAG_MTX_SPIN) { err = msleep_spin(pps, pps->driver_mtx, |