Hi, ipmi(4) is one of the few remaining callers of tsleep(9). I want to convert it to use tsleep_nsec(9) but I need some clarification on what the code in question is doing.
In ipmi_poll_thread() we initialize all the sensors in a loop. Between each get_sdr() call we tsleep(9) for 1 tick. So, I wonder: 1. Why do we sleep here? Is get_sdr() slow and we don't want to hog the CPU? We block for a tick to let other stuff run? Or is there some other reason? 2. Why are we spinning until tsleep(9) returns EWOULDBLOCK? Can another thread interrupt the sleep with a wakeup(9)? marco@ added the tsleep(9) loop in this commit: http://cvsweb.openbsd.org/src/sys/dev/ipmi.c?rev=1.59&content-type=text/x-cvsweb-markup Any ideas? My guess is that the attached diff will work fine but if we could remove the loop while we're here that would simplify the code. Index: ipmi.c =================================================================== RCS file: /cvs/src/sys/dev/ipmi.c,v retrieving revision 1.112 diff -u -p -r1.112 ipmi.c --- ipmi.c 29 Mar 2020 09:31:10 -0000 1.112 +++ ipmi.c 2 Dec 2020 20:31:57 -0000 @@ -1497,7 +1497,8 @@ ipmi_poll_thread(void *arg) printf("%s: no SDRs IPMI disabled\n", DEVNAME(sc)); goto done; } - while (tsleep(sc, PWAIT, "ipmirun", 1) != EWOULDBLOCK) + while (tsleep_nsec(sc, PWAIT, "ipmirun", + MSEC_TO_NSEC(1)) != EWOULDBLOCK) continue; }
