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| author | Konstantin Belousov <kib@FreeBSD.org> | 2016-07-21 16:34:56 +0000 |
|---|---|---|
| committer | Konstantin Belousov <kib@FreeBSD.org> | 2016-07-21 16:34:56 +0000 |
| commit | 9837947b07a67c89a1ae88ca883df5e0b142b618 (patch) | |
| tree | 99028bdec5601f45dbfbd4586b77a286cff58778 /sys/kern/subr_prf.c | |
| parent | 303c356245bb3e7efab29e776b941d733a8f77bc (diff) | |
| download | src-9837947b07a67c89a1ae88ca883df5e0b142b618.tar.gz src-9837947b07a67c89a1ae88ca883df5e0b142b618.zip | |
Provide counter_warning(9) KPI which allows to issue limited number of
warnings for some kernel events, mostly intended for the use of
obsoleted or otherwise undersired interfaces.
This is an abstracted and race-expelled code from compat pty driver.
Requested and reviewed by: jhb
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D7270
Notes
Notes:
svn path=/head/; revision=303151
Diffstat (limited to 'sys/kern/subr_prf.c')
| -rw-r--r-- | sys/kern/subr_prf.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/sys/kern/subr_prf.c b/sys/kern/subr_prf.c index 5bcf39b9400b..5f9796e7d876 100644 --- a/sys/kern/subr_prf.c +++ b/sys/kern/subr_prf.c @@ -1196,3 +1196,22 @@ sbuf_hexdump(struct sbuf *sb, const void *ptr, int length, const char *hdr, } } +void +counted_warning(unsigned *counter, const char *msg) +{ + struct thread *td; + unsigned c; + + for (;;) { + c = *counter; + if (c == 0) + break; + if (atomic_cmpset_int(counter, c, c - 1)) { + td = curthread; + log(LOG_INFO, "pid %d (%s) %s%s\n", + td->td_proc->p_pid, td->td_name, msg, + c > 1 ? "" : " - not logging anymore"); + break; + } + } +} |