- 31 10月, 2008 1 次提交
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由 Jan Beulich 提交于
Impact: cleanup Signed-off-by: NJan Beulich <jbeulich@novell.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 22 10月, 2008 1 次提交
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由 Andy Henroid 提交于
The Intel 7300 Memory Controller supports dynamic throttling of memory which can be used to save power when system is idle. This driver does the memory throttling when all CPUs are idle on such a system. Refer to "Intel 7300 Memory Controller Hub (MCH)" datasheet for the config space description. Signed-off-by: NAndy Henroid <andrew.d.henroid@intel.com> Signed-off-by: NLen Brown <len.brown@intel.com> Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
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- 20 10月, 2008 1 次提交
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由 Matt Helsley 提交于
This patch implements a new freezer subsystem in the control groups framework. It provides a way to stop and resume execution of all tasks in a cgroup by writing in the cgroup filesystem. The freezer subsystem in the container filesystem defines a file named freezer.state. Writing "FROZEN" to the state file will freeze all tasks in the cgroup. Subsequently writing "RUNNING" will unfreeze the tasks in the cgroup. Reading will return the current state. * Examples of usage : # mkdir /containers/freezer # mount -t cgroup -ofreezer freezer /containers # mkdir /containers/0 # echo $some_pid > /containers/0/tasks to get status of the freezer subsystem : # cat /containers/0/freezer.state RUNNING to freeze all tasks in the container : # echo FROZEN > /containers/0/freezer.state # cat /containers/0/freezer.state FREEZING # cat /containers/0/freezer.state FROZEN to unfreeze all tasks in the container : # echo RUNNING > /containers/0/freezer.state # cat /containers/0/freezer.state RUNNING This is the basic mechanism which should do the right thing for user space task in a simple scenario. It's important to note that freezing can be incomplete. In that case we return EBUSY. This means that some tasks in the cgroup are busy doing something that prevents us from completely freezing the cgroup at this time. After EBUSY, the cgroup will remain partially frozen -- reflected by freezer.state reporting "FREEZING" when read. The state will remain "FREEZING" until one of these things happens: 1) Userspace cancels the freezing operation by writing "RUNNING" to the freezer.state file 2) Userspace retries the freezing operation by writing "FROZEN" to the freezer.state file (writing "FREEZING" is not legal and returns EIO) 3) The tasks that blocked the cgroup from entering the "FROZEN" state disappear from the cgroup's set of tasks. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: export thaw_process] Signed-off-by: NCedric Le Goater <clg@fr.ibm.com> Signed-off-by: NMatt Helsley <matthltc@us.ibm.com> Acked-by: NSerge E. Hallyn <serue@us.ibm.com> Tested-by: NMatt Helsley <matthltc@us.ibm.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 17 10月, 2008 2 次提交
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由 Venkatesh Pallipadi 提交于
http://bugzilla.kernel.org/show_bug.cgi?id=11345Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: NLen Brown <len.brown@intel.com>
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由 Jan Beulich 提交于
Using "def_bool n" is pointless, simply using bool here appears more appropriate. Further, retaining such options that don't have a prompt and aren't selected by anything seems also at least questionable. Signed-off-by: NJan Beulich <jbeulich@novell.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Tony Luck <tony.luck@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Cc: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 16 10月, 2008 7 次提交
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由 Thomas Gleixner 提交于
Revert the dynarray changes. They need more thought and polishing. Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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由 Thomas Gleixner 提交于
This code is not ready yet. Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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由 Yinghai Lu 提交于
Ingo said sparse_irq is some intrusive. need to make it selectable to make it simple, remove irq_desc as parameter in some functions. (ack, eoi, set_affinity). may need to make member if irq_chip to take irq_desc, or struct irq later. Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Yinghai Lu 提交于
but actually irq still needs to be less than NR_IRQS, because interrupt[NR_IRQS] in entry.S. need to enable per_cpu vector... Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Yinghai Lu 提交于
This has been deprecated for years, the user space irqbalanced utility works better with numa, has configurable policies, etc... Signed-off-by: NYinghai Lu <yhlu.kernel@gmai.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Yinghai Lu 提交于
add CONFIG_HAVE_SPARSE_IRQ to for use condensed array. Get rid of irq_desc[] array assumptions. Preallocate 32 irq_desc, and irq_desc() will try to get more. ( No change in functionality is expected anywhere, except the odd build failure where we missed a code site or where a crossing commit itroduces new irq_desc[] usage. ) v2: according to Eric, change get_irq_desc() to irq_desc() Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Yinghai Lu 提交于
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 14 10月, 2008 1 次提交
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由 Steven Rostedt 提交于
Enable the use of the __mcount_loc infrastructure on x86_64 and i386. Signed-off-by: NSteven Rostedt <srostedt@redhat.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 13 10月, 2008 2 次提交
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由 Ingo Molnar 提交于
additional_cpus=<x> parameter is dangerous and broken: for example if we boot additional_cpus=-2 on a stock dual-core system it will crash the box on bootup. So reduce the maze of code a bit by removingthe user-configurability angle. Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Chuck Ebbert 提交于
x86: allow number of additional hotplug CPUs to be set at compile time, V2 The default number of additional CPU IDs for hotplugging is determined by asking ACPI or mptables how many "disabled" CPUs there are in the system, but many systems get this wrong so that e.g. a uniprocessor machine gets an extra CPU allocated and never switches to single CPU mode. And sometimes CPU hotplugging is enabled only for suspend/hibernate anyway, so the additional CPU IDs are not wanted. Allow the number to be set to zero at compile time. Also, force the number of extra CPUs to zero if hotplugging is disabled which allows removing some conditional code. Tested on uniprocessor x86_64 that ACPI claims has a disabled processor, with CPU hotplugging configured. ("After" has the number of additional CPUs set to 0) Before: NR_CPUS: 512, nr_cpu_ids: 2, nr_node_ids 1 After: NR_CPUS: 512, nr_cpu_ids: 1, nr_node_ids 1 [Changed the name of the option and the prompt according to Ingo's suggestion.] Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 01 10月, 2008 1 次提交
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由 Yinghai Lu 提交于
This option has been added in v2.6.26 as a default-disabled feature and went through several revisions since then. The feature fixes a wide range of MTRR setup problems that BIOSes leave us with: slow system, slow Xorg, slow system when adding lots of RAM, etc., so we want to enable it by default for v2.6.28. See: [Bug 10508] Upgrade to 4GB of RAM messes up MTRRs http://bugzilla.kernel.org/show_bug.cgi?id=10508 and the test results in: http://lkml.org/lkml/2008/9/29/273 1. hpa reg00: base=0xc0000000 (3072MB), size=1024MB: uncachable, count=1 reg01: base=0x13c000000 (5056MB), size= 64MB: uncachable, count=1 reg02: base=0x00000000 ( 0MB), size=4096MB: write-back, count=1 reg03: base=0x100000000 (4096MB), size=1024MB: write-back, count=1 reg04: base=0xbf700000 (3063MB), size= 1MB: uncachable, count=1 reg05: base=0xbf800000 (3064MB), size= 8MB: uncachable, count=1 will get Found optimal setting for mtrr clean up gran_size: 1M chunk_size: 128M num_reg: 6 lose RAM: 0M range0: 0000000000000000 - 00000000c0000000 Setting variable MTRR 0, base: 0MB, range: 2048MB, type WB Setting variable MTRR 1, base: 2048MB, range: 1024MB, type WB hole: 00000000bf700000 - 00000000c0000000 Setting variable MTRR 2, base: 3063MB, range: 1MB, type UC Setting variable MTRR 3, base: 3064MB, range: 8MB, type UC range0: 0000000100000000 - 0000000140000000 Setting variable MTRR 4, base: 4096MB, range: 1024MB, type WB hole: 000000013c000000 - 0000000140000000 Setting variable MTRR 5, base: 5056MB, range: 64MB, type UC 2. Dylan Taft reg00: base=0x00000000 ( 0MB), size=4096MB: write-back, count=1 reg01: base=0x100000000 (4096MB), size= 512MB: write-back, count=1 reg02: base=0x120000000 (4608MB), size= 256MB: write-back, count=1 reg03: base=0xd0000000 (3328MB), size= 256MB: uncachable, count=1 reg04: base=0xe0000000 (3584MB), size= 512MB: uncachable, count=1 reg05: base=0xc7e00000 (3198MB), size= 2MB: uncachable, count=1 reg06: base=0xc8000000 (3200MB), size= 128MB: uncachable, count=1 will get Found optimal setting for mtrr clean up gran_size: 1M chunk_size: 4M num_reg: 6 lose RAM: 0M range0: 0000000000000000 - 00000000c8000000 Setting variable MTRR 0, base: 0MB, range: 2048MB, type WB Setting variable MTRR 1, base: 2048MB, range: 1024MB, type WB Setting variable MTRR 2, base: 3072MB, range: 128MB, type WB hole: 00000000c7e00000 - 00000000c8000000 Setting variable MTRR 3, base: 3198MB, range: 2MB, type UC rangeX: 0000000100000000 - 0000000130000000 Setting variable MTRR 4, base: 4096MB, range: 512MB, type WB Setting variable MTRR 5, base: 4608MB, range: 256MB, type WB 3. Gabriel reg00: base=0xd0000000 (3328MB), size= 256MB: uncachable, count=1 reg01: base=0xe0000000 (3584MB), size= 512MB: uncachable, count=1 reg02: base=0x00000000 ( 0MB), size=4096MB: write-back, count=1 reg03: base=0x100000000 (4096MB), size= 512MB: write-back, count=1 reg04: base=0x120000000 (4608MB), size= 128MB: write-back, count=1 reg05: base=0x128000000 (4736MB), size= 64MB: write-back, count=1 reg06: base=0xcf600000 (3318MB), size= 2MB: uncachable, count=1 will get Found optimal setting for mtrr clean up gran_size: 1M chunk_size: 16M num_reg: 7 lose RAM: 0M range0: 0000000000000000 - 00000000d0000000 Setting variable MTRR 0, base: 0MB, range: 2048MB, type WB Setting variable MTRR 1, base: 2048MB, range: 1024MB, type WB Setting variable MTRR 2, base: 3072MB, range: 256MB, type WB hole: 00000000cf600000 - 00000000cf800000 Setting variable MTRR 3, base: 3318MB, range: 2MB, type UC rangeX: 0000000100000000 - 000000012c000000 Setting variable MTRR 4, base: 4096MB, range: 512MB, type WB Setting variable MTRR 5, base: 4608MB, range: 128MB, type WB Setting variable MTRR 6, base: 4736MB, range: 64MB, type WB 4. Mika Fischer reg00: base=0xc0000000 (3072MB), size=1024MB: uncachable, count=1 reg01: base=0x00000000 ( 0MB), size=4096MB: write-back, count=1 reg02: base=0x100000000 (4096MB), size=1024MB: write-back, count=1 reg03: base=0xbf700000 (3063MB), size= 1MB: uncachable, count=1 reg04: base=0xbf800000 (3064MB), size= 8MB: uncachable, count=1 will get Found optimal setting for mtrr clean up gran_size: 1M chunk_size: 16M num_reg: 5 lose RAM: 0M range0: 0000000000000000 - 00000000c0000000 Setting variable MTRR 0, base: 0MB, range: 2048MB, type WB Setting variable MTRR 1, base: 2048MB, range: 1024MB, type WB hole: 00000000bf700000 - 00000000c0000000 Setting variable MTRR 2, base: 3063MB, range: 1MB, type UC Setting variable MTRR 3, base: 3064MB, range: 8MB, type UC rangeX: 0000000100000000 - 0000000140000000 Setting variable MTRR 4, base: 4096MB, range: 1024MB, type WB Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 23 9月, 2008 1 次提交
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由 Dmitry Adamushko 提交于
Combine both generic and arch-specific parts of microcode into a single module (arch-specific parts are config-dependent). Also while we are at it, move arch-specific parts from microcode.h into their respective arch-specific .c files. Signed-off-by: NDmitry Adamushko <dmitry.adamushko@gmail.com> Cc: "Peter Oruba" <peter.oruba@amd.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 19 9月, 2008 1 次提交
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由 Joerg Roedel 提交于
The AMD IOMMU can generate interrupts for various reasons. This patch adds the basic interrupt enabling infrastructure to the driver. Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 16 9月, 2008 1 次提交
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由 Ingo Molnar 提交于
This bugzilla: http://bugzilla.kernel.org/show_bug.cgi?id=11237 Documents a wide range of systems where the BIOS utilizes the first 64K of physical memory during suspend/resume and other hardware events. Currently we reserve this memory on all AMI and Phoenix BIOS systems. Life is too short to hunt subtle memory corruption problems like this, so we try to be robust by default. Still, allow this to be overriden: allow users who want that first 64K of memory to be available to the kernel disable the quirk, via CONFIG_X86_RESERVE_LOW_64K=n. Also, allow the early reservation to overlap with other early reservations. Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 14 9月, 2008 3 次提交
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由 Jeremy Fitzhardinge 提交于
There's no good reason why a resource_size_t shouldn't just be a physical address, so simply redefine it in terms of phys_addr_t. Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Jeremy Fitzhardinge 提交于
Add a kernel-wide "phys_addr_t" which is guaranteed to be able to hold any physical address. By default it equals the word size of the architecture, but a 32-bit architecture can set ARCH_PHYS_ADDR_T_64BIT if it needs a 64-bit phys_addr_t. Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Alexey Dobriyan 提交于
X86_64 part is entirely redundant. Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 09 9月, 2008 1 次提交
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由 Alexey Dobriyan 提交于
seccomp is prctl(2)-driven now. Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 07 9月, 2008 5 次提交
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由 Jeremy Fitzhardinge 提交于
Default the low memory corruption check to off, but make the default setting of the memory_corruption_check kernel parameter a config parameter. Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Jeremy Fitzhardinge 提交于
The corruption check is enabled in Kconfig by default, but disabled at runtime. This patch adds several kernel parameters to control the corruption check's behaviour; these are documented in kernel-parameters.txt. Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Jeremy Fitzhardinge 提交于
Some BIOSes have been observed to corrupt memory in the low 64k. This change: - Reserves all memory which does not have to be in that area, to prevent it from being used as general memory by the kernel. Things like the SMP trampoline are still in the memory, however. - Clears the reserved memory so we can observe changes to it. - Adds a function check_for_bios_corruption() which checks and reports on memory becoming unexpectedly non-zero. Currently it's called in the x86 fault handler, and the powermanagement debug output. Signed-off-by: NJeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 David Woodhouse 提交于
HAVE_AOUT doesn't quite do the same thing as the recently removed ARCH_SUPPORTS_AOUT config option. That was set even on platforms where binfmt_aout isn't supported, although it's not entirely clear why. So it's best just to introduce a new symbol, handled consistently with other similar HAVE_xxx symbols; with a simple 'select' in the arch Kconfig. Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
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由 David Woodhouse 提交于
We don't need this any more; arguably we never really did. Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
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- 26 8月, 2008 1 次提交
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由 Linus Torvalds 提交于
This fixes a regression that was indirectly caused by commit 1184dc2f ("x86: modify Kconfig to allow up to 4096 cpus"). Allowing 4k CPU's is not practical at this time, because we still have a number of places that have several 'cpumask_t's on the stack, and a 4k-bit cpumask is 512 bytes of stack-space for each such variable. This literally caused functions like 'smp_call_function_mask' to have a 2.5kB stack frame, and several functions to have 2kB stackframes. With an 8kB stack total, smashing the stack was simply much too likely. At least bugzilla entry http://bugzilla.kernel.org/show_bug.cgi?id=11342 was due to this. The earlier commit to not inline load_module() into sys_init_module() fixed the particular symptoms of this that Alan Brunelle saw in that bugzilla entry, but the huge stack waste by cpumask_t's was the more direct cause. Some day we'll have allocation helpers that allocate large CPU masks dynamically, but in the meantime we simply cannot allow cpumasks this large. Cc: Alan D. Brunelle <Alan.Brunelle@hp.com> Cc: Mike Travis <travis@sgi.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 15 8月, 2008 2 次提交
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由 Tim Bird 提交于
Allow x86 to support a built-in kernel command line. The built-in command line can override the one provided by the boot loader, for those cases where the boot loader is broken or it is difficult to change the command line in the the boot loader. H. Peter Anvin wrote: > Ingo Molnar wrote: >> Best would be to make it really apparent in the code that nothing >> changes if this config option is not set. Preferably there should be >> no extra code at all in that case. >> > > I would like to see this: [...Nested ifdefs...] OK. This version changes absolutely nothing if CONFIG_CMDLINE_BOOL is not set (the default). Also, no space is appended even when CONFIG_CMDLINE_BOOL is set, but the builtin string is empty. This is less sloppy all the way around, IMHO. Note that I use the same option names as on other arches for this feature. [ mingo@elte.hu: build fix ] Signed-off-by: NTim Bird <tim.bird@am.sony.com> Cc: Matt Mackall <mpm@selenic.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Pavel Machek 提交于
Adjust experimental tags in Kconfig, update config to notice that i386/x86_64 is now single architecture. Signed-off-by: NPavel Machek <pavel@suse.cz> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 12 8月, 2008 3 次提交
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由 Rusty Russell 提交于
Out of line get_user_pages_fast fallback implementation, make it a weak symbol, get rid of CONFIG_HAVE_GET_USER_PAGES_FAST. Export the symbol to modules so lguest can use it. Signed-off-by: NNick Piggin <npiggin@suse.de> Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
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由 Jeff Chua 提交于
With CONFIG_X86_PC, I can set CONFIG_SPARSEMEM=y. With CONFIG_X86_GENERICARCH, CONFIG_SPARSEMEM depends on CONFIG_NUMA. I'm using the patch below to enable sparsemem instead of flatmem. System booted and is running. Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Dimitri Sivanich 提交于
This removes the EXPERIMENTAL restriction from CONFIG_HOTPLUG_CPU on the x86 architecture. Signed-off-by: NDimitri Sivanich <sivanich@sgi.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 29 7月, 2008 2 次提交
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由 Peter Oruba 提交于
This patch introduces microcode patch loading for AMD processors. It is based on previous corresponding work for Intel processors. It hooks into the general patch loading module. Main difference is that a container file format is used to hold all patch data for multiple processors as well as an equivalent CPU table, which comes seperately, as opposed to Intel's microcode patching solution. Kconfig and Makefile have been changed provice config and build option for new source file. Signed-off-by: NPeter Oruba <peter.oruba@amd.com> Cc: Tigran Aivazian <tigran@aivazian.fsnet.co.uk> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Peter Oruba 提交于
Refactored code by introducing a two-module solution. There is one general module in which vendor specific modules can hook into. However, that is exclusive, there is only one vendor specific module allowed at a time. A CPU vendor check makes sure only the correct module for the underlying system gets called. Functinally in terms of patch loading itself there are no changes. This refactoring provides a basis for future implementations of other vendors' patch loaders. Signed-off-by: NPeter Oruba <peter.oruba@amd.com> Cc: Tigran Aivazian <tigran@aivazian.fsnet.co.uk> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 28 7月, 2008 1 次提交
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由 Randy Dunlap 提交于
Move mtrr.txt to the Documentation/x86/ subdirectory. Add 00-INDEX to the Documentation/x86/ subdirectory. Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com> Cc: Adrian Bunk <bunk@kernel.org> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 27 7月, 2008 3 次提交
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由 Roland McGrath 提交于
The x86 arch code has all the prerequisites, so set HAVE_ARCH_TRACEHOOK. Signed-off-by: NRoland McGrath <roland@redhat.com>
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由 Nick Piggin 提交于
Implement get_user_pages_fast without locking in the fastpath on x86. Do an optimistic lockless pagetable walk, without taking mmap_sem or any page table locks or even mmap_sem. Page table existence is guaranteed by turning interrupts off (combined with the fact that we're always looking up the current mm, means we can do the lockless page table walk within the constraints of the TLB shootdown design). Basically we can do this lockless pagetable walk in a similar manner to the way the CPU's pagetable walker does not have to take any locks to find present ptes. This patch (combined with the subsequent ones to convert direct IO to use it) was found to give about 10% performance improvement on a 2 socket 8 core Intel Xeon system running an OLTP workload on DB2 v9.5 "To test the effects of the patch, an OLTP workload was run on an IBM x3850 M2 server with 2 processors (quad-core Intel Xeon processors at 2.93 GHz) using IBM DB2 v9.5 running Linux 2.6.24rc7 kernel. Comparing runs with and without the patch resulted in an overall performance benefit of ~9.8%. Correspondingly, oprofiles showed that samples from __up_read and __down_read routines that is seen during thread contention for system resources was reduced from 2.8% down to .05%. Monitoring the /proc/vmstat output from the patched run showed that the counter for fast_gup contained a very high number while the fast_gup_slow value was zero." (fast_gup is the old name for get_user_pages_fast, fast_gup_slow is a counter we had for the number of times the slowpath was invoked). The main reason for the improvement is that DB2 has multiple threads each issuing direct-IO. Direct-IO uses get_user_pages, and thus the threads contend the mmap_sem cacheline, and can also contend on page table locks. I would anticipate larger performance gains on larger systems, however I think DB2 uses an adaptive mix of threads and processes, so it could be that thread contention remains pretty constant as machine size increases. In which case, we stuck with "only" a 10% gain. The downside of using get_user_pages_fast is that if there is not a pte with the correct permissions for the access, we end up falling back to get_user_pages and so the get_user_pages_fast is a bit of extra work. However this should not be the common case in most performance critical code. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: Kconfig fix] [akpm@linux-foundation.org: Makefile fix/cleanup] [akpm@linux-foundation.org: warning fix] Signed-off-by: NNick Piggin <npiggin@suse.de> Cc: Dave Kleikamp <shaggy@austin.ibm.com> Cc: Andy Whitcroft <apw@shadowen.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andi Kleen <andi@firstfloor.org> Cc: Dave Kleikamp <shaggy@austin.ibm.com> Cc: Badari Pulavarty <pbadari@us.ibm.com> Cc: Zach Brown <zach.brown@oracle.com> Cc: Jens Axboe <jens.axboe@oracle.com> Reviewed-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Huang Ying 提交于
This patch implements devices state save/restore before after kexec. This patch together with features in kexec_jump patch can be used for following: - A simple hibernation implementation without ACPI support. You can kexec a hibernating kernel, save the memory image of original system and shutdown the system. When resuming, you restore the memory image of original system via ordinary kexec load then jump back. - Kernel/system debug through making system snapshot. You can make system snapshot, jump back, do some thing and make another system snapshot. - Cooperative multi-kernel/system. With kexec jump, you can switch between several kernels/systems quickly without boot process except the first time. This appears like swap a whole kernel/system out/in. - A general method to call program in physical mode (paging turning off). This can be used to invoke BIOS code under Linux. The following user-space tools can be used with kexec jump: - kexec-tools needs to be patched to support kexec jump. The patches and the precompiled kexec can be download from the following URL: source: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec-tools-src_git_kh10.tar.bz2 patches: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec-tools-patches_git_kh10.tar.bz2 binary: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec_git_kh10 - makedumpfile with patches are used as memory image saving tool, it can exclude free pages from original kernel memory image file. The patches and the precompiled makedumpfile can be download from the following URL: source: http://khibernation.sourceforge.net/download/release_v10/makedumpfile/makedumpfile-src_cvs_kh10.tar.bz2 patches: http://khibernation.sourceforge.net/download/release_v10/makedumpfile/makedumpfile-patches_cvs_kh10.tar.bz2 binary: http://khibernation.sourceforge.net/download/release_v10/makedumpfile/makedumpfile_cvs_kh10 - An initramfs image can be used as the root file system of kexeced kernel. An initramfs image built with "BuildRoot" can be downloaded from the following URL: initramfs image: http://khibernation.sourceforge.net/download/release_v10/initramfs/rootfs_cvs_kh10.gz All user space tools above are included in the initramfs image. Usage example of simple hibernation: 1. Compile and install patched kernel with following options selected: CONFIG_X86_32=y CONFIG_RELOCATABLE=y CONFIG_KEXEC=y CONFIG_CRASH_DUMP=y CONFIG_PM=y CONFIG_HIBERNATION=y CONFIG_KEXEC_JUMP=y 2. Build an initramfs image contains kexec-tool and makedumpfile, or download the pre-built initramfs image, called rootfs.gz in following text. 3. Prepare a partition to save memory image of original kernel, called hibernating partition in following text. 4. Boot kernel compiled in step 1 (kernel A). 5. In the kernel A, load kernel compiled in step 1 (kernel B) with /sbin/kexec. The shell command line can be as follow: /sbin/kexec --load-preserve-context /boot/bzImage --mem-min=0x100000 --mem-max=0xffffff --initrd=rootfs.gz 6. Boot the kernel B with following shell command line: /sbin/kexec -e 7. The kernel B will boot as normal kexec. In kernel B the memory image of kernel A can be saved into hibernating partition as follow: jump_back_entry=`cat /proc/cmdline | tr ' ' '\n' | grep kexec_jump_back_entry | cut -d '='` echo $jump_back_entry > kexec_jump_back_entry cp /proc/vmcore dump.elf Then you can shutdown the machine as normal. 8. Boot kernel compiled in step 1 (kernel C). Use the rootfs.gz as root file system. 9. In kernel C, load the memory image of kernel A as follow: /sbin/kexec -l --args-none --entry=`cat kexec_jump_back_entry` dump.elf 10. Jump back to the kernel A as follow: /sbin/kexec -e Then, kernel A is resumed. Implementation point: To support jumping between two kernels, before jumping to (executing) the new kernel and jumping back to the original kernel, the devices are put into quiescent state, and the state of devices and CPU is saved. After jumping back from kexeced kernel and jumping to the new kernel, the state of devices and CPU are restored accordingly. The devices/CPU state save/restore code of software suspend is called to implement corresponding function. Known issues: - Because the segment number supported by sys_kexec_load is limited, hibernation image with many segments may not be load. This is planned to be eliminated by adding a new flag to sys_kexec_load to make a image can be loaded with multiple sys_kexec_load invoking. Now, only the i386 architecture is supported. Signed-off-by: NHuang Ying <ying.huang@intel.com> Acked-by: NVivek Goyal <vgoyal@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Nigel Cunningham <nigel@nigel.suspend2.net> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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