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* Move most of the contents of opt_compat.h to opt_global.h.Brooks Davis2018-04-061-2/+0
| | | | | | | | | | | | | | | | | | | | | opt_compat.h is mentioned in nearly 180 files. In-progress network driver compabibility improvements may add over 100 more so this is closer to "just about everywhere" than "only some files" per the guidance in sys/conf/options. Keep COMPAT_LINUX32 in opt_compat.h as it is confined to a subset of sys/compat/linux/*.c. A fake _COMPAT_LINUX option ensure opt_compat.h is created on all architectures. Move COMPAT_LINUXKPI to opt_dontuse.h as it is only used to control the set of compiled files. Reviewed by: kib, cem, jhb, jtl Sponsored by: DARPA, AFRL Differential Revision: https://reviews.freebsd.org/D14941 Notes: svn path=/head/; revision=332122
* sys/kern: adoption of SPDX licensing ID tags.Pedro F. Giffuni2017-11-271-0/+2
| | | | | | | | | | | | | | | Mainly focus on files that use BSD 2-Clause license, however the tool I was using misidentified many licenses so this was mostly a manual - error prone - task. The Software Package Data Exchange (SPDX) group provides a specification to make it easier for automated tools to detect and summarize well known opensource licenses. We are gradually adopting the specification, noting that the tags are considered only advisory and do not, in any way, superceed or replace the license texts. Notes: svn path=/head/; revision=326271
* Update the vdso timehands only via tc_windup().Neel Natu2015-01-201-2/+3
| | | | | | | | | | | | Prior to this change CLOCK_MONOTONIC could go backwards when the timecounter hardware was changed via 'sysctl kern.timecounter.hardware'. This happened because the vdso timehands update was missing the special treatment in tc_windup() when changing timecounters. Reviewed by: kib Notes: svn path=/head/; revision=277406
* Implement mechanism to export some kernel timekeeping data toKonstantin Belousov2012-06-221-0/+49
usermode, using shared page. The structures and functions have vdso prefix, to indicate the intended location of the code in some future. The versioned per-algorithm data is exported in the format of struct vdso_timehands, which mostly repeats the content of in-kernel struct timehands. Usermode reading of the structure can be lockless. Compatibility export for 32bit processes on 64bit host is also provided. Kernel also provides usermode with indication about currently used timecounter, so that libc can fall back to syscall if configured timecounter is unknown to usermode code. The shared data updates are initiated both from the tc_windup(), where a fast task is queued to do the update, and from sysctl handlers which change timecounter. A manual override switch kern.timecounter.fast_gettime allows to turn off the mechanism. Only x86 architectures export the real algorithm data, and there, only for tsc timecounter. HPET counters page could be exported as well, but I prefer to not further glue the kernel and libc ABI there until proper vdso-based solution is developed. Minimal stubs neccessary for non-x86 architectures to still compile are provided. Discussed with: bde Reviewed by: jhb Tested by: flo MFC after: 1 month Notes: svn path=/head/; revision=237433