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authorLinus Torvalds <torvalds@g5.osdl.org>2006-09-26 16:07:55 -0400
committerLinus Torvalds <torvalds@g5.osdl.org>2006-09-26 16:07:55 -0400
commitb278240839e20fa9384ea430df463b367b90e04e (patch)
treef99f0c8cdd4cc7f177cd75440e6bd181cded7fb3 /Documentation
parentdd77a4ee0f3981693d4229aa1d57cea9e526ff47 (diff)
parent3f75f42d7733e73aca5c78326489efd4189e0111 (diff)
Merge branch 'for-linus' of git://one.firstfloor.org/home/andi/git/linux-2.6
* 'for-linus' of git://one.firstfloor.org/home/andi/git/linux-2.6: (225 commits) [PATCH] Don't set calgary iommu as default y [PATCH] i386/x86-64: New Intel feature flags [PATCH] x86: Add a cumulative thermal throttle event counter. [PATCH] i386: Make the jiffies compares use the 64bit safe macros. [PATCH] x86: Refactor thermal throttle processing [PATCH] Add 64bit jiffies compares (for use with get_jiffies_64) [PATCH] Fix unwinder warning in traps.c [PATCH] x86: Allow disabling early pci scans with pci=noearly or disallowing conf1 [PATCH] x86: Move direct PCI scanning functions out of line [PATCH] i386/x86-64: Make all early PCI scans dependent on CONFIG_PCI [PATCH] Don't leak NT bit into next task [PATCH] i386/x86-64: Work around gcc bug with noreturn functions in unwinder [PATCH] Fix some broken white space in ia32_signal.c [PATCH] Initialize argument registers for 32bit signal handlers. [PATCH] Remove all traces of signal number conversion [PATCH] Don't synchronize time reading on single core AMD systems [PATCH] Remove outdated comment in x86-64 mmconfig code [PATCH] Use string instructions for Core2 copy/clear [PATCH] x86: - restore i8259A eoi status on resume [PATCH] i386: Split multi-line printk in oops output. ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/HOWTO3
-rw-r--r--Documentation/filesystems/proc.txt14
-rw-r--r--Documentation/kbuild/makefiles.txt5
-rw-r--r--Documentation/kernel-parameters.txt6
-rw-r--r--Documentation/x86_64/boot-options.txt7
-rw-r--r--Documentation/x86_64/kernel-stacks99
6 files changed, 127 insertions, 7 deletions
diff --git a/Documentation/HOWTO b/Documentation/HOWTO
index 915ae8c986c6..1d6560413cc5 100644
--- a/Documentation/HOWTO
+++ b/Documentation/HOWTO
@@ -358,7 +358,8 @@ Here is a list of some of the different kernel trees available:
358 quilt trees: 358 quilt trees:
359 - USB, PCI, Driver Core, and I2C, Greg Kroah-Hartman <gregkh@suse.de> 359 - USB, PCI, Driver Core, and I2C, Greg Kroah-Hartman <gregkh@suse.de>
360 kernel.org/pub/linux/kernel/people/gregkh/gregkh-2.6/ 360 kernel.org/pub/linux/kernel/people/gregkh/gregkh-2.6/
361 361 - x86-64, partly i386, Andi Kleen <ak@suse.de>
362 ftp.firstfloor.org:/pub/ak/x86_64/quilt/
362 363
363Bug Reporting 364Bug Reporting
364------------- 365-------------
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index 99902ae6804e..7db71d6fba82 100644
--- a/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@ -1124,11 +1124,15 @@ debugging information is displayed on console.
1124NMI switch that most IA32 servers have fires unknown NMI up, for example. 1124NMI switch that most IA32 servers have fires unknown NMI up, for example.
1125If a system hangs up, try pressing the NMI switch. 1125If a system hangs up, try pressing the NMI switch.
1126 1126
1127[NOTE] 1127nmi_watchdog
1128 This function and oprofile share a NMI callback. Therefore this function 1128------------
1129 cannot be enabled when oprofile is activated. 1129
1130 And NMI watchdog will be disabled when the value in this file is set to 1130Enables/Disables the NMI watchdog on x86 systems. When the value is non-zero
1131 non-zero. 1131the NMI watchdog is enabled and will continuously test all online cpus to
1132determine whether or not they are still functioning properly.
1133
1134Because the NMI watchdog shares registers with oprofile, by disabling the NMI
1135watchdog, oprofile may have more registers to utilize.
1132 1136
1133 1137
11342.4 /proc/sys/vm - The virtual memory subsystem 11382.4 /proc/sys/vm - The virtual memory subsystem
diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt
index b7d6abb501a6..e2cbd59cf2d0 100644
--- a/Documentation/kbuild/makefiles.txt
+++ b/Documentation/kbuild/makefiles.txt
@@ -421,6 +421,11 @@ more details, with real examples.
421 The second argument is optional, and if supplied will be used 421 The second argument is optional, and if supplied will be used
422 if first argument is not supported. 422 if first argument is not supported.
423 423
424 as-instr
425 as-instr checks if the assembler reports a specific instruction
426 and then outputs either option1 or option2
427 C escapes are supported in the test instruction
428
424 cc-option 429 cc-option
425 cc-option is used to check if $(CC) supports a given option, and not 430 cc-option is used to check if $(CC) supports a given option, and not
426 supported to use an optional second option. 431 supported to use an optional second option.
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 766abdab94e7..c918cc3f65fb 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1240,7 +1240,11 @@ running once the system is up.
1240 bootloader. This is currently used on 1240 bootloader. This is currently used on
1241 IXP2000 systems where the bus has to be 1241 IXP2000 systems where the bus has to be
1242 configured a certain way for adjunct CPUs. 1242 configured a certain way for adjunct CPUs.
1243 1243 noearly [X86] Don't do any early type 1 scanning.
1244 This might help on some broken boards which
1245 machine check when some devices' config space
1246 is read. But various workarounds are disabled
1247 and some IOMMU drivers will not work.
1244 pcmv= [HW,PCMCIA] BadgePAD 4 1248 pcmv= [HW,PCMCIA] BadgePAD 4
1245 1249
1246 pd. [PARIDE] 1250 pd. [PARIDE]
diff --git a/Documentation/x86_64/boot-options.txt b/Documentation/x86_64/boot-options.txt
index 6da24e7a56cb..4303e0c12476 100644
--- a/Documentation/x86_64/boot-options.txt
+++ b/Documentation/x86_64/boot-options.txt
@@ -245,6 +245,13 @@ Debugging
245 newfallback: use new unwinder but fall back to old if it gets 245 newfallback: use new unwinder but fall back to old if it gets
246 stuck (default) 246 stuck (default)
247 247
248 call_trace=[old|both|newfallback|new]
249 old: use old inexact backtracer
250 new: use new exact dwarf2 unwinder
251 both: print entries from both
252 newfallback: use new unwinder but fall back to old if it gets
253 stuck (default)
254
248Misc 255Misc
249 256
250 noreplacement Don't replace instructions with more appropriate ones 257 noreplacement Don't replace instructions with more appropriate ones
diff --git a/Documentation/x86_64/kernel-stacks b/Documentation/x86_64/kernel-stacks
new file mode 100644
index 000000000000..bddfddd466ab
--- /dev/null
+++ b/Documentation/x86_64/kernel-stacks
@@ -0,0 +1,99 @@
1Most of the text from Keith Owens, hacked by AK
2
3x86_64 page size (PAGE_SIZE) is 4K.
4
5Like all other architectures, x86_64 has a kernel stack for every
6active thread. These thread stacks are THREAD_SIZE (2*PAGE_SIZE) big.
7These stacks contain useful data as long as a thread is alive or a
8zombie. While the thread is in user space the kernel stack is empty
9except for the thread_info structure at the bottom.
10
11In addition to the per thread stacks, there are specialized stacks
12associated with each cpu. These stacks are only used while the kernel
13is in control on that cpu, when a cpu returns to user space the
14specialized stacks contain no useful data. The main cpu stacks is
15
16* Interrupt stack. IRQSTACKSIZE
17
18 Used for external hardware interrupts. If this is the first external
19 hardware interrupt (i.e. not a nested hardware interrupt) then the
20 kernel switches from the current task to the interrupt stack. Like
21 the split thread and interrupt stacks on i386 (with CONFIG_4KSTACKS),
22 this gives more room for kernel interrupt processing without having
23 to increase the size of every per thread stack.
24
25 The interrupt stack is also used when processing a softirq.
26
27Switching to the kernel interrupt stack is done by software based on a
28per CPU interrupt nest counter. This is needed because x86-64 "IST"
29hardware stacks cannot nest without races.
30
31x86_64 also has a feature which is not available on i386, the ability
32to automatically switch to a new stack for designated events such as
33double fault or NMI, which makes it easier to handle these unusual
34events on x86_64. This feature is called the Interrupt Stack Table
35(IST). There can be up to 7 IST entries per cpu. The IST code is an
36index into the Task State Segment (TSS), the IST entries in the TSS
37point to dedicated stacks, each stack can be a different size.
38
39An IST is selected by an non-zero value in the IST field of an
40interrupt-gate descriptor. When an interrupt occurs and the hardware
41loads such a descriptor, the hardware automatically sets the new stack
42pointer based on the IST value, then invokes the interrupt handler. If
43software wants to allow nested IST interrupts then the handler must
44adjust the IST values on entry to and exit from the interrupt handler.
45(this is occasionally done, e.g. for debug exceptions)
46
47Events with different IST codes (i.e. with different stacks) can be
48nested. For example, a debug interrupt can safely be interrupted by an
49NMI. arch/x86_64/kernel/entry.S::paranoidentry adjusts the stack
50pointers on entry to and exit from all IST events, in theory allowing
51IST events with the same code to be nested. However in most cases, the
52stack size allocated to an IST assumes no nesting for the same code.
53If that assumption is ever broken then the stacks will become corrupt.
54
55The currently assigned IST stacks are :-
56
57* STACKFAULT_STACK. EXCEPTION_STKSZ (PAGE_SIZE).
58
59 Used for interrupt 12 - Stack Fault Exception (#SS).
60
61 This allows to recover from invalid stack segments. Rarely
62 happens.
63
64* DOUBLEFAULT_STACK. EXCEPTION_STKSZ (PAGE_SIZE).
65
66 Used for interrupt 8 - Double Fault Exception (#DF).
67
68 Invoked when handling a exception causes another exception. Happens
69 when the kernel is very confused (e.g. kernel stack pointer corrupt)
70 Using a separate stack allows to recover from it well enough in many
71 cases to still output an oops.
72
73* NMI_STACK. EXCEPTION_STKSZ (PAGE_SIZE).
74
75 Used for non-maskable interrupts (NMI).
76
77 NMI can be delivered at any time, including when the kernel is in the
78 middle of switching stacks. Using IST for NMI events avoids making
79 assumptions about the previous state of the kernel stack.
80
81* DEBUG_STACK. DEBUG_STKSZ
82
83 Used for hardware debug interrupts (interrupt 1) and for software
84 debug interrupts (INT3).
85
86 When debugging a kernel, debug interrupts (both hardware and
87 software) can occur at any time. Using IST for these interrupts
88 avoids making assumptions about the previous state of the kernel
89 stack.
90
91* MCE_STACK. EXCEPTION_STKSZ (PAGE_SIZE).
92
93 Used for interrupt 18 - Machine Check Exception (#MC).
94
95 MCE can be delivered at any time, including when the kernel is in the
96 middle of switching stacks. Using IST for MCE events avoids making
97 assumptions about the previous state of the kernel stack.
98
99For more details see the Intel IA32 or AMD AMD64 architecture manuals.