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| author |   pirofti <pirofti@openbsd.org> | 2020-07-06 13:33:05 +0000 |
|---|---|---|
| committer | pirofti <pirofti@openbsd.org> | 2020-07-06 13:33:05 +0000 |
| commit | d82e6535c6efd8305182f77041b2246ccfae1196 (patch) | |
| tree | d28dc130334c17949d90330ecbb2121294b899ff /sys/dev/pv/pvclock.c | |
| parent | sync (diff) | |
| download | wireguard-openbsd-d82e6535c6efd8305182f77041b2246ccfae1196.tar.xz wireguard-openbsd-d82e6535c6efd8305182f77041b2246ccfae1196.zip | |
Add support for timeconting in userland.
This diff exposes parts of clock_gettime(2) and gettimeofday(2) to
userland via libc eliberating processes from the need for a context
switch everytime they want to count the passage of time.
If a timecounter clock can be exposed to userland than it needs to set
its tc_user member to a non-zero value. Tested with one or multiple
counters per architecture.
The timing data is shared through a pointer found in the new ELF
auxiliary vector AUX_openbsd_timekeep containing timehands information
that is frequently updated by the kernel.
Timing differences between the last kernel update and the current time
are adjusted in userland by the tc_get_timecount() function inside the
MD usertc.c file.
This permits a much more responsive environment, quite visible in
browsers, office programs and gaming (apparently one is are able to fly
in Minecraft now).
Tested by robert@, sthen@, naddy@, kmos@, phessler@, and many others!
OK from at least kettenis@, cheloha@, naddy@, sthen@
Diffstat (limited to 'sys/dev/pv/pvclock.c')
| -rw-r--r-- | sys/dev/pv/pvclock.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/sys/dev/pv/pvclock.c b/sys/dev/pv/pvclock.c index 6b242f7448d..cf72aecedcc 100644 --- a/sys/dev/pv/pvclock.c +++ b/sys/dev/pv/pvclock.c @@ -1,4 +1,4 @@ -/* $OpenBSD: pvclock.c,v 1.5 2019/12/13 06:43:46 pd Exp $ */ +/* $OpenBSD: pvclock.c,v 1.6 2020/07/06 13:33:09 pirofti Exp $ */ /* * Copyright (c) 2018 Reyk Floeter <reyk@openbsd.org> @@ -74,7 +74,7 @@ struct cfdriver pvclock_cd = { }; struct timecounter pvclock_timecounter = { - pvclock_get_timecount, NULL, ~0u, 0, NULL, -2000, NULL + pvclock_get_timecount, NULL, ~0u, 0, NULL, -2000, NULL, 0 }; int |