diff options
Diffstat (limited to 'Documentation/admin-guide/kernel-parameters.txt')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 95 |
1 files changed, 71 insertions, 24 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index af7104aaffd9..512ccafa45b1 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -114,7 +114,6 @@ This facility can be used to prevent such uncontrolled GPE floodings. Format: <int> - Support masking of GPEs numbered from 0x00 to 0x7f. acpi_no_auto_serialize [HW,ACPI] Disable auto-serialization of AML methods @@ -223,7 +222,7 @@ acpi_sleep= [HW,ACPI] Sleep options Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig, - old_ordering, nonvs, sci_force_enable } + old_ordering, nonvs, sci_force_enable, nobl } See Documentation/power/video.txt for information on s3_bios and s3_mode. s3_beep is for debugging; it makes the PC's speaker beep @@ -239,6 +238,9 @@ sci_force_enable causes the kernel to set SCI_EN directly on resume from S1/S3 (which is against the ACPI spec, but some broken systems don't work without it). + nobl causes the internal blacklist of systems known to + behave incorrectly in some ways with respect to system + suspend and resume to be ignored (use wisely). acpi_use_timer_override [HW,ACPI] Use timer override. For some broken Nvidia NF5 boards @@ -644,6 +646,20 @@ console=brl,ttyS0 For now, only VisioBraille is supported. + console_msg_format= + [KNL] Change console messages format + default + By default we print messages on consoles in + "[time stamp] text\n" format (time stamp may not be + printed, depending on CONFIG_PRINTK_TIME or + `printk_time' param). + syslog + Switch to syslog format: "<%u>[time stamp] text\n" + IOW, each message will have a facility and loglevel + prefix. The format is similar to one used by syslog() + syscall, or to executing "dmesg -S --raw" or to reading + from /proc/kmsg. + consoleblank= [KNL] The console blank (screen saver) timeout in seconds. A value of 0 disables the blank timer. Defaults to 0. @@ -713,9 +729,6 @@ It will be ignored when crashkernel=X,high is not used or memory reserved is below 4G. - crossrelease_fullstack - [KNL] Allow to record full stack trace in cross-release - cryptomgr.notests [KNL] Disable crypto self-tests @@ -2053,9 +2066,6 @@ This tests the locking primitive's ability to transition abruptly to and from idle. - locktorture.torture_runnable= [BOOT] - Start locktorture running at boot time. - locktorture.torture_type= [KNL] Specify the locking implementation to test. @@ -2542,6 +2552,9 @@ This is useful when you use a panic=... timeout and need the box quickly up again. + These settings can be accessed at runtime via + the nmi_watchdog and hardlockup_panic sysctls. + netpoll.carrier_timeout= [NET] Specifies amount of time (in seconds) that netpoll should wait for a carrier. By default netpoll @@ -2626,6 +2639,11 @@ nosmt [KNL,S390] Disable symmetric multithreading (SMT). Equivalent to smt=1. + nospectre_v2 [X86] Disable all mitigations for the Spectre variant 2 + (indirect branch prediction) vulnerability. System may + allow data leaks with this option, which is equivalent + to spectre_v2=off. + noxsave [BUGS=X86] Disables x86 extended register state save and restore using xsave. The kernel will fallback to enabling legacy floating-point and sse state. @@ -2712,8 +2730,6 @@ steal time is computed, but won't influence scheduler behaviour - nopti [X86-64] Disable kernel page table isolation - nolapic [X86-32,APIC] Do not enable or use the local APIC. nolapic_timer [X86-32,APIC] Do not use the local APIC timer. @@ -2742,8 +2758,6 @@ norandmaps Don't use address space randomization. Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space - noreplace-paravirt [X86,IA-64,PV_OPS] Don't patch paravirt_ops - noreplace-smp [X86-32,SMP] Don't replace SMP instructions with UP alternatives @@ -3100,6 +3114,12 @@ pcie_scan_all Scan all possible PCIe devices. Otherwise we only look for one device below a PCIe downstream port. + big_root_window Try to add a big 64bit memory window to the PCIe + root complex on AMD CPUs. Some GFX hardware + can resize a BAR to allow access to all VRAM. + Adding the window is slightly risky (it may + conflict with unreported devices), so this + taints the kernel. pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power Management. @@ -3288,11 +3308,20 @@ pt. [PARIDE] See Documentation/blockdev/paride.txt. - pti= [X86_64] - Control user/kernel address space isolation: - on - enable - off - disable - auto - default setting + pti= [X86_64] Control Page Table Isolation of user and + kernel address spaces. Disabling this feature + removes hardening, but improves performance of + system calls and interrupts. + + on - unconditionally enable + off - unconditionally disable + auto - kernel detects whether your CPU model is + vulnerable to issues that PTI mitigates + + Not specifying this option is equivalent to pti=auto. + + nopti [X86_64] + Equivalent to pti=off pty.legacy_count= [KNL] Number of legacy pty's. Overwrites compiled-in @@ -3471,9 +3500,6 @@ the same as for rcuperf.nreaders. N, where N is the number of CPUs - rcuperf.perf_runnable= [BOOT] - Start rcuperf running at boot time. - rcuperf.perf_type= [KNL] Specify the RCU implementation to test. @@ -3607,9 +3633,6 @@ Test RCU's dyntick-idle handling. See also the rcutorture.shuffle_interval parameter. - rcutorture.torture_runnable= [BOOT] - Start rcutorture running at boot time. - rcutorture.torture_type= [KNL] Specify the RCU implementation to test. @@ -3667,7 +3690,8 @@ rdt= [HW,X86,RDT] Turn on/off individual RDT features. List is: - cmt, mbmtotal, mbmlocal, l3cat, l3cdp, l2cat, mba. + cmt, mbmtotal, mbmlocal, l3cat, l3cdp, l2cat, l2cdp, + mba. E.g. to turn on cmt and turn off mba use: rdt=cmt,!mba @@ -3943,6 +3967,29 @@ sonypi.*= [HW] Sony Programmable I/O Control Device driver See Documentation/laptops/sonypi.txt + spectre_v2= [X86] Control mitigation of Spectre variant 2 + (indirect branch speculation) vulnerability. + + on - unconditionally enable + off - unconditionally disable + auto - kernel detects whether your CPU model is + vulnerable + + Selecting 'on' will, and 'auto' may, choose a + mitigation method at run time according to the + CPU, the available microcode, the setting of the + CONFIG_RETPOLINE configuration option, and the + compiler with which the kernel was built. + + Specific mitigations can also be selected manually: + + retpoline - replace indirect branches + retpoline,generic - google's original retpoline + retpoline,amd - AMD-specific minimal thunk + + Not specifying this option is equivalent to + spectre_v2=auto. + spia_io_base= [HW,MTD] spia_fio_base= spia_pedr= |