Author: kib Date: Thu Jul 21 16:34:56 2016 New Revision: 303151 URL: https://svnweb.freebsd.org/changeset/base/303151
Log: 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 Modified: head/sys/dev/pty/pty.c head/sys/kern/subr_prf.c head/sys/sys/systm.h Modified: head/sys/dev/pty/pty.c ============================================================================== --- head/sys/dev/pty/pty.c Thu Jul 21 15:48:41 2016 (r303150) +++ head/sys/dev/pty/pty.c Thu Jul 21 16:34:56 2016 (r303151) @@ -52,10 +52,10 @@ __FBSDID("$FreeBSD$"); * binary emulation. */ -static unsigned int pty_warningcnt = 1; +static unsigned pty_warningcnt = 1; SYSCTL_UINT(_kern, OID_AUTO, tty_pty_warningcnt, CTLFLAG_RW, - &pty_warningcnt, 0, - "Warnings that will be triggered upon legacy PTY allocation"); + &pty_warningcnt, 0, + "Warnings that will be triggered upon legacy PTY allocation"); static int ptydev_fdopen(struct cdev *dev, int fflags, struct thread *td, struct file *fp) @@ -77,12 +77,7 @@ ptydev_fdopen(struct cdev *dev, int ffla } /* Raise a warning when a legacy PTY has been allocated. */ - if (pty_warningcnt > 0) { - pty_warningcnt--; - log(LOG_INFO, "pid %d (%s) is using legacy pty devices%s\n", - td->td_proc->p_pid, td->td_name, - pty_warningcnt ? "" : " - not logging anymore"); - } + counted_warning(&pty_warningcnt, "is using legacy pty devices"); return (0); } Modified: head/sys/kern/subr_prf.c ============================================================================== --- head/sys/kern/subr_prf.c Thu Jul 21 15:48:41 2016 (r303150) +++ head/sys/kern/subr_prf.c Thu Jul 21 16:34:56 2016 (r303151) @@ -1196,3 +1196,22 @@ sbuf_hexdump(struct sbuf *sb, const void } } +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; + } + } +} Modified: head/sys/sys/systm.h ============================================================================== --- head/sys/sys/systm.h Thu Jul 21 15:48:41 2016 (r303150) +++ head/sys/sys/systm.h Thu Jul 21 16:34:56 2016 (r303151) @@ -447,4 +447,6 @@ void intr_prof_stack_use(struct thread * extern void (*softdep_ast_cleanup)(void); +void counted_warning(unsigned *counter, const char *msg); + #endif /* !_SYS_SYSTM_H_ */ _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
