others).
ccw_timeout_log [S390]
- See Documentation/s390/common_io.rst for details.
+ See Documentation/arch/s390/common_io.rst for details.
cgroup_disable= [KNL] Disable a particular controller or optional feature
Format: {name of the controller(s) or feature(s) to disable}
Setting checkreqprot to 1 is deprecated.
cio_ignore= [S390]
- See Documentation/s390/common_io.rst for details.
+ See Documentation/arch/s390/common_io.rst for details.
clearcpuid=X[,X...] [X86]
Disable CPUID feature X for the kernel. See
Format: off | on
default: on
+ gather_data_sampling=
+ [X86,INTEL] Control the Gather Data Sampling (GDS)
+ mitigation.
+
+ Gather Data Sampling is a hardware vulnerability which
+ allows unprivileged speculative access to data which was
+ previously stored in vector registers.
+
+ This issue is mitigated by default in updated microcode.
+ The mitigation may have a performance impact but can be
+ disabled. On systems without the microcode mitigation
+ disabling AVX serves as a mitigation.
+
+ force: Disable AVX to mitigate systems without
+ microcode mitigation. No effect if the microcode
+ mitigation is present. Known to cause crashes in
+ userspace with buggy AVX enumeration.
+
+ off: Disable GDS mitigation.
+
gcov_persist= [GCOV] When non-zero (default), profiling data for
kernel modules is saved and remains accessible via
debugfs, even when the module is unloaded/reloaded.
locktorture.torture_type= [KNL]
Specify the locking implementation to test.
+ locktorture.writer_fifo= [KNL]
+ Run the write-side locktorture kthreads at
+ sched_set_fifo() real-time priority.
+
locktorture.verbose= [KNL]
Enable additional printk() statements.
Disable all optional CPU mitigations. This
improves system performance, but it may also
expose users to several CPU vulnerabilities.
- Equivalent to: nopti [X86,PPC]
- if nokaslr then kpti=0 [ARM64]
- nospectre_v1 [X86,PPC]
- nobp=0 [S390]
- nospectre_v2 [X86,PPC,S390,ARM64]
- spectre_v2_user=off [X86]
- spec_store_bypass_disable=off [X86,PPC]
- ssbd=force-off [ARM64]
- nospectre_bhb [ARM64]
+ Equivalent to: if nokaslr then kpti=0 [ARM64]
+ gather_data_sampling=off [X86]
+ kvm.nx_huge_pages=off [X86]
l1tf=off [X86]
mds=off [X86]
- tsx_async_abort=off [X86]
- kvm.nx_huge_pages=off [X86]
- srbds=off [X86,INTEL]
+ mmio_stale_data=off [X86]
no_entry_flush [PPC]
no_uaccess_flush [PPC]
- mmio_stale_data=off [X86]
+ nobp=0 [S390]
+ nopti [X86,PPC]
+ nospectre_bhb [ARM64]
+ nospectre_v1 [X86,PPC]
+ nospectre_v2 [X86,PPC,S390,ARM64]
retbleed=off [X86]
+ spec_store_bypass_disable=off [X86,PPC]
+ spectre_v2_user=off [X86]
+ srbds=off [X86,INTEL]
+ ssbd=force-off [ARM64]
+ tsx_async_abort=off [X86]
Exceptions:
This does not have any effect on
test until boot completes in order to avoid
interference.
+ rcuscale.kfree_by_call_rcu= [KNL]
+ In kernels built with CONFIG_RCU_LAZY=y, test
+ call_rcu() instead of kfree_rcu().
+
+ rcuscale.kfree_mult= [KNL]
+ Instead of allocating an object of size kfree_obj,
+ allocate one of kfree_mult * sizeof(kfree_obj).
+ Defaults to 1.
+
rcuscale.kfree_rcu_test= [KNL]
Set to measure performance of kfree_rcu() flooding.
Number of loops doing rcuscale.kfree_alloc_num number
of allocations and frees.
+ rcuscale.minruntime= [KNL]
+ Set the minimum test run time in seconds. This
+ does not affect the data-collection interval,
+ but instead allows better measurement of things
+ like CPU consumption.
+
rcuscale.nreaders= [KNL]
Set number of RCU readers. The value -1 selects
N, where N is the number of CPUs. A value
the same as for rcuscale.nreaders.
N, where N is the number of CPUs
- rcuscale.perf_type= [KNL]
+ rcuscale.scale_type= [KNL]
Specify the RCU implementation to test.
rcuscale.shutdown= [KNL]
in microseconds. The default of zero says
no holdoff.
+ rcuscale.writer_holdoff_jiffies= [KNL]
+ Additional write-side holdoff between grace
+ periods, but in jiffies. The default of zero
+ says no holdoff.
+
rcutorture.fqs_duration= [KNL]
Set duration of force_quiescent_state bursts
in microseconds.
number avoids disturbing real-time workloads,
but lengthens grace periods.
+ rcupdate.rcu_task_lazy_lim= [KNL]
+ Number of callbacks on a given CPU that will
+ cancel laziness on that CPU. Use -1 to disable
+ cancellation of laziness, but be advised that
+ doing so increases the danger of OOM due to
+ callback flooding.
+
rcupdate.rcu_task_stall_info= [KNL]
Set initial timeout in jiffies for RCU task stall
informational messages, which give some indication
A change in value does not take effect until
the beginning of the next grace period.
+ rcupdate.rcu_tasks_lazy_ms= [KNL]
+ Set timeout in milliseconds RCU Tasks asynchronous
+ callback batching for call_rcu_tasks().
+ A negative value will take the default. A value
+ of zero will disable batching. Batching is
+ always disabled for synchronize_rcu_tasks().
+
+ rcupdate.rcu_tasks_rude_lazy_ms= [KNL]
+ Set timeout in milliseconds RCU Tasks
+ Rude asynchronous callback batching for
+ call_rcu_tasks_rude(). A negative value
+ will take the default. A value of zero will
+ disable batching. Batching is always disabled
+ for synchronize_rcu_tasks_rude().
+
+ rcupdate.rcu_tasks_trace_lazy_ms= [KNL]
+ Set timeout in milliseconds RCU Tasks
+ Trace asynchronous callback batching for
+ call_rcu_tasks_trace(). A negative value
+ will take the default. A value of zero will
+ disable batching. Batching is always disabled
+ for synchronize_rcu_tasks_trace().
+
rcupdate.rcu_self_test= [KNL]
Run the RCU early boot self tests
Useful for devices that are detected asynchronously
(e.g. USB and MMC devices).
+ rootwait= [KNL] Maximum time (in seconds) to wait for root device
+ to show up before attempting to mount the root
+ filesystem.
+
rproc_mem=nn[KMG][@address]
[KNL,ARM,CMA] Remoteproc physical memory block.
Memory area to be used by remote processor image,
Not specifying this option is equivalent to
spectre_v2_user=auto.
+ spec_rstack_overflow=
+ [X86] Control RAS overflow mitigation on AMD Zen CPUs
+
+ off - Disable mitigation
+ microcode - Enable microcode mitigation only
+ safe-ret - Enable sw-only safe RET mitigation (default)
+ ibpb - Enable mitigation by issuing IBPB on
+ kernel entry
+ ibpb-vmexit - Issue IBPB only on VMEXIT
+ (cloud-specific mitigation)
+
spec_store_bypass_disable=
[HW] Control Speculative Store Bypass (SSB) Disable mitigation
(Speculative Store Bypass vulnerability)
-1: disable all critical trip points in all thermal zones
<degrees C>: override all critical trip points
- thermal.nocrt= [HW,ACPI]
- Set to disable actions on ACPI thermal zone
- critical and hot trip points.
-
thermal.off= [HW,ACPI]
1: disable ACPI thermal control
This will guarantee that all the other pcrs
are saved.
+ tpm_tis.interrupts= [HW,TPM]
+ Enable interrupts for the MMIO based physical layer
+ for the FIFO interface. By default it is set to false
+ (0). For more information about TPM hardware interfaces
+ defined by Trusted Computing Group (TCG) see
+ https://trustedcomputinggroup.org/resource/pc-client-platform-tpm-profile-ptp-specification/
+
tp_printk [FTRACE]
Have the tracepoints sent to printk as well as the
tracing ring buffer. This is useful for early boot up
projects / platform / kernel / linux-rpi.git / blobdiff