diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/x86_64/boot-options.txt | 27 | ||||
| -rw-r--r-- | Documentation/x86_64/cpu-hotplug-spec | 2 | ||||
| -rw-r--r-- | Documentation/x86_64/kernel-stacks | 26 | ||||
| -rw-r--r-- | Documentation/x86_64/mm.txt | 22 |
4 files changed, 35 insertions, 42 deletions
diff --git a/Documentation/x86_64/boot-options.txt b/Documentation/x86_64/boot-options.txt index 0d653993f361..625a21db0c2a 100644 --- a/Documentation/x86_64/boot-options.txt +++ b/Documentation/x86_64/boot-options.txt @@ -226,9 +226,9 @@ IOMMU (input/output memory management unit) is 20. memaper[=<order>] Allocate an own aperture over RAM with size 32MB<<order. (default: order=1, i.e. 64MB) - merge Do scather-gather (SG) merging. Implies "force" + merge Do scatter-gather (SG) merging. Implies "force" (experimental). - nomerge Don't do scather-gather (SG) merging. + nomerge Don't do scatter-gather (SG) merging. noaperture Ask the IOMMU not to touch the aperture for AGP. forcesac Force single-address cycle (SAC) mode for masks <40bits (experimental). @@ -275,14 +275,14 @@ IOMMU (input/output memory management unit) Debugging - oops=panic Always panic on oopses. Default is to just kill the process, - but there is a small probability of deadlocking the machine. - This will also cause panics on machine check exceptions. - Useful together with panic=30 to trigger a reboot. + oops=panic Always panic on oopses. Default is to just kill the process, + but there is a small probability of deadlocking the machine. + This will also cause panics on machine check exceptions. + Useful together with panic=30 to trigger a reboot. - kstack=N Print that many words from the kernel stack in oops dumps. + kstack=N Print N words from the kernel stack in oops dumps. - pagefaulttrace Dump all page faults. Only useful for extreme debugging + pagefaulttrace Dump all page faults. Only useful for extreme debugging and will create a lot of output. call_trace=[old|both|newfallback|new] @@ -292,15 +292,8 @@ Debugging newfallback: use new unwinder but fall back to old if it gets stuck (default) - call_trace=[old|both|newfallback|new] - old: use old inexact backtracer - new: use new exact dwarf2 unwinder - both: print entries from both - newfallback: use new unwinder but fall back to old if it gets - stuck (default) - -Misc +Miscellaneous noreplacement Don't replace instructions with more appropriate ones for the CPU. This may be useful on asymmetric MP systems - where some CPU have less capabilities than the others. + where some CPUs have less capabilities than others. diff --git a/Documentation/x86_64/cpu-hotplug-spec b/Documentation/x86_64/cpu-hotplug-spec index 5c0fa345e556..3c23e0587db3 100644 --- a/Documentation/x86_64/cpu-hotplug-spec +++ b/Documentation/x86_64/cpu-hotplug-spec @@ -2,7 +2,7 @@ Firmware support for CPU hotplug under Linux/x86-64 --------------------------------------------------- Linux/x86-64 supports CPU hotplug now. For various reasons Linux wants to -know in advance boot time the maximum number of CPUs that could be plugged +know in advance of boot time the maximum number of CPUs that could be plugged into the system. ACPI 3.0 currently has no official way to supply this information from the firmware to the operating system. diff --git a/Documentation/x86_64/kernel-stacks b/Documentation/x86_64/kernel-stacks index bddfddd466ab..5ad65d51fb95 100644 --- a/Documentation/x86_64/kernel-stacks +++ b/Documentation/x86_64/kernel-stacks @@ -9,9 +9,9 @@ zombie. While the thread is in user space the kernel stack is empty except for the thread_info structure at the bottom. In addition to the per thread stacks, there are specialized stacks -associated with each cpu. These stacks are only used while the kernel -is in control on that cpu, when a cpu returns to user space the -specialized stacks contain no useful data. The main cpu stacks is +associated with each CPU. These stacks are only used while the kernel +is in control on that CPU; when a CPU returns to user space the +specialized stacks contain no useful data. The main CPU stacks are: * Interrupt stack. IRQSTACKSIZE @@ -32,17 +32,17 @@ x86_64 also has a feature which is not available on i386, the ability to automatically switch to a new stack for designated events such as double fault or NMI, which makes it easier to handle these unusual events on x86_64. This feature is called the Interrupt Stack Table -(IST). There can be up to 7 IST entries per cpu. The IST code is an -index into the Task State Segment (TSS), the IST entries in the TSS -point to dedicated stacks, each stack can be a different size. +(IST). There can be up to 7 IST entries per CPU. The IST code is an +index into the Task State Segment (TSS). The IST entries in the TSS +point to dedicated stacks; each stack can be a different size. -An IST is selected by an non-zero value in the IST field of an +An IST is selected by a non-zero value in the IST field of an interrupt-gate descriptor. When an interrupt occurs and the hardware loads such a descriptor, the hardware automatically sets the new stack pointer based on the IST value, then invokes the interrupt handler. If software wants to allow nested IST interrupts then the handler must adjust the IST values on entry to and exit from the interrupt handler. -(this is occasionally done, e.g. for debug exceptions) +(This is occasionally done, e.g. for debug exceptions.) Events with different IST codes (i.e. with different stacks) can be nested. For example, a debug interrupt can safely be interrupted by an @@ -58,17 +58,17 @@ The currently assigned IST stacks are :- Used for interrupt 12 - Stack Fault Exception (#SS). - This allows to recover from invalid stack segments. Rarely + This allows the CPU to recover from invalid stack segments. Rarely happens. * DOUBLEFAULT_STACK. EXCEPTION_STKSZ (PAGE_SIZE). Used for interrupt 8 - Double Fault Exception (#DF). - Invoked when handling a exception causes another exception. Happens - when the kernel is very confused (e.g. kernel stack pointer corrupt) - Using a separate stack allows to recover from it well enough in many - cases to still output an oops. + Invoked when handling one exception causes another exception. Happens + when the kernel is very confused (e.g. kernel stack pointer corrupt). + Using a separate stack allows the kernel to recover from it well enough + in many cases to still output an oops. * NMI_STACK. EXCEPTION_STKSZ (PAGE_SIZE). diff --git a/Documentation/x86_64/mm.txt b/Documentation/x86_64/mm.txt index 133561b9cb0c..f42798ed1c54 100644 --- a/Documentation/x86_64/mm.txt +++ b/Documentation/x86_64/mm.txt @@ -3,26 +3,26 @@ Virtual memory map with 4 level page tables: -0000000000000000 - 00007fffffffffff (=47bits) user space, different per mm +0000000000000000 - 00007fffffffffff (=47 bits) user space, different per mm hole caused by [48:63] sign extension -ffff800000000000 - ffff80ffffffffff (=40bits) guard hole -ffff810000000000 - ffffc0ffffffffff (=46bits) direct mapping of all phys. memory -ffffc10000000000 - ffffc1ffffffffff (=40bits) hole -ffffc20000000000 - ffffe1ffffffffff (=45bits) vmalloc/ioremap space +ffff800000000000 - ffff80ffffffffff (=40 bits) guard hole +ffff810000000000 - ffffc0ffffffffff (=46 bits) direct mapping of all phys. memory +ffffc10000000000 - ffffc1ffffffffff (=40 bits) hole +ffffc20000000000 - ffffe1ffffffffff (=45 bits) vmalloc/ioremap space ... unused hole ... -ffffffff80000000 - ffffffff82800000 (=40MB) kernel text mapping, from phys 0 +ffffffff80000000 - ffffffff82800000 (=40 MB) kernel text mapping, from phys 0 ... unused hole ... -ffffffff88000000 - fffffffffff00000 (=1919MB) module mapping space +ffffffff88000000 - fffffffffff00000 (=1919 MB) module mapping space -The direct mapping covers all memory in the system upto the highest +The direct mapping covers all memory in the system up to the highest memory address (this means in some cases it can also include PCI memory -holes) +holes). vmalloc space is lazily synchronized into the different PML4 pages of the processes using the page fault handler, with init_level4_pgt as reference. -Current X86-64 implementations only support 40 bit of address space, -but we support upto 46bits. This expands into MBZ space in the page tables. +Current X86-64 implementations only support 40 bits of address space, +but we support up to 46 bits. This expands into MBZ space in the page tables. -Andi Kleen, Jul 2004 |