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author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-07-08 11:59:59 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-07-08 11:59:59 -0700 |
commit | 13324c42c1401ad838208ee1e98f3821fce1cd86 (patch) | |
tree | 2ea97f4686d4149eb2322eac63751fdacf1dedaf /Documentation | |
parent | ab2486a9ee3243c8342549f58a13cdfa9abb497a (diff) | |
parent | 049331f277fef1c3f2527c2c9afa1d285e9a1247 (diff) | |
download | linux-13324c42c1401ad838208ee1e98f3821fce1cd86.tar.bz2 |
Merge branch 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 CPU feature updates from Thomas Gleixner:
"Updates for x86 CPU features:
- Support for UMWAIT/UMONITOR, which allows to use MWAIT and MONITOR
instructions in user space to save power e.g. in HPC workloads
which spin wait on synchronization points.
The maximum time a MWAIT can halt in userspace is controlled by the
kernel and can be adjusted by the sysadmin.
- Speed up the MTRR handling code on CPUs which support cache
self-snooping correctly.
On those CPUs the wbinvd() invocations can be omitted which speeds
up the MTRR setup by a factor of 50.
- Support for the new x86 vendor Zhaoxin who develops processors
based on the VIA Centaur technology.
- Prevent 'cat /proc/cpuinfo' from affecting isolated NOHZ_FULL CPUs
by sending IPIs to retrieve the CPU frequency and use the cached
values instead.
- The addition and late revert of the FSGSBASE support. The revert
was required as it turned out that the code still has hard to
diagnose issues. Yet another engineering trainwreck...
- Small fixes, cleanups, improvements and the usual new Intel CPU
family/model addons"
* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits)
x86/fsgsbase: Revert FSGSBASE support
selftests/x86/fsgsbase: Fix some test case bugs
x86/entry/64: Fix and clean up paranoid_exit
x86/entry/64: Don't compile ignore_sysret if 32-bit emulation is enabled
selftests/x86: Test SYSCALL and SYSENTER manually with TF set
x86/mtrr: Skip cache flushes on CPUs with cache self-snooping
x86/cpu/intel: Clear cache self-snoop capability in CPUs with known errata
Documentation/ABI: Document umwait control sysfs interfaces
x86/umwait: Add sysfs interface to control umwait maximum time
x86/umwait: Add sysfs interface to control umwait C0.2 state
x86/umwait: Initialize umwait control values
x86/cpufeatures: Enumerate user wait instructions
x86/cpu: Disable frequency requests via aperfmperf IPI for nohz_full CPUs
x86/acpi/cstate: Add Zhaoxin processors support for cache flush policy in C3
ACPI, x86: Add Zhaoxin processors support for NONSTOP TSC
x86/cpu: Create Zhaoxin processors architecture support file
x86/cpu: Split Tremont based Atoms from the rest
Documentation/x86/64: Add documentation for GS/FS addressing mode
x86/elf: Enumerate kernel FSGSBASE capability in AT_HWCAP2
x86/cpu: Enable FSGSBASE on 64bit by default and add a chicken bit
...
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/ABI/testing/sysfs-devices-system-cpu | 23 | ||||
-rw-r--r-- | Documentation/process/changes.rst | 6 |
2 files changed, 25 insertions, 4 deletions
diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index 1528239f69b2..923fe2001472 100644 --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -538,3 +538,26 @@ Description: Intel Energy and Performance Bias Hint (EPB) This attribute is present for all online CPUs supporting the Intel EPB feature. + +What: /sys/devices/system/cpu/umwait_control + /sys/devices/system/cpu/umwait_control/enable_c02 + /sys/devices/system/cpu/umwait_control/max_time +Date: May 2019 +Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> +Description: Umwait control + + enable_c02: Read/write interface to control umwait C0.2 state + Read returns C0.2 state status: + 0: C0.2 is disabled + 1: C0.2 is enabled + + Write 'y' or '1' or 'on' to enable C0.2 state. + Write 'n' or '0' or 'off' to disable C0.2 state. + + The interface is case insensitive. + + max_time: Read/write interface to control umwait maximum time + in TSC-quanta that the CPU can reside in either C0.1 + or C0.2 state. The time is an unsigned 32-bit number. + Note that a value of zero means there is no limit. + Low order two bits must be zero. diff --git a/Documentation/process/changes.rst b/Documentation/process/changes.rst index 18735dc460a0..0a18075c485e 100644 --- a/Documentation/process/changes.rst +++ b/Documentation/process/changes.rst @@ -31,7 +31,7 @@ you probably needn't concern yourself with isdn4k-utils. ====================== =============== ======================================== GNU C 4.6 gcc --version GNU make 3.81 make --version -binutils 2.20 ld -v +binutils 2.21 ld -v flex 2.5.35 flex --version bison 2.0 bison --version util-linux 2.10o fdformat --version @@ -77,9 +77,7 @@ You will need GNU make 3.81 or later to build the kernel. Binutils -------- -The build system has, as of 4.13, switched to using thin archives (`ar T`) -rather than incremental linking (`ld -r`) for built-in.a intermediate steps. -This requires binutils 2.20 or newer. +Binutils 2.21 or newer is needed to build the kernel. pkg-config ---------- |