diff options
Diffstat (limited to 'src/ev_evports.c')
| -rw-r--r-- | src/ev_evports.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/src/ev_evports.c b/src/ev_evports.c index 07676e6..ee357bc 100644 --- a/src/ev_evports.c +++ b/src/ev_evports.c @@ -185,6 +185,14 @@ static void _do_poll(struct poller *p, int exp, int wake) do { int timeout = (global.tune.options & GTUNE_BUSY_POLLING) ? 0 : wait_time; int interrupted = 0; + /* Note: normally we should probably expect to pass + * global.tune.maxpollevents here so as to process multiple + * events at once, but it appears unreliable in tests, even + * starting with value 2, and it seems basically nobody's + * using that anymore so it's probably not worth spending days + * investigating this poller more to improve its performance, + * let's switch back to 1. --WT + */ nevlist = 1; /* desired number of events to be retrieved */ timeout_ts.tv_sec = (timeout / 1000); timeout_ts.tv_nsec = (timeout % 1000) * 1000000; @@ -194,6 +202,12 @@ static void _do_poll(struct poller *p, int exp, int wake) evports_evlist_max, &nevlist, /* updated to the number of events retrieved */ &timeout_ts); + + /* Be careful, nevlist here is always updated by the syscall + * even on status == -1, so it must always be respected + * otherwise events are lost. Awkward API BTW, I wonder how + * they thought ENOSYS ought to be handled... -WT + */ if (status != 0) { int e = errno; switch (e) { @@ -206,7 +220,7 @@ static void _do_poll(struct poller *p, int exp, int wake) /* nevlist >= 0 */ break; default: - nevlist = 0; + /* signal or anything else */ interrupted = 1; break; } |