aboutsummaryrefslogtreecommitdiff
path: root/Documentation/x86_64
AgeCommit message (Collapse)Author
2007-07-21x86_64: mcelog tolerant level cleanupTim Hockin
Background: The MCE handler has several paths that it can take, depending on various conditions of the MCE status and the value of the 'tolerant' knob. The exact semantics are not well defined and the code is a bit twisty. Description: This patch makes the MCE handler's behavior more clear by documenting the behavior for various 'tolerant' levels. It also fixes or enhances several small things in the handler. Specifically: * If RIPV is set it is not safe to restart, so set the 'no way out' flag rather than the 'kill it' flag. * Don't panic() on correctable MCEs. * If the _OVER bit is set *and* the _UC bit is set (meaning possibly dropped uncorrected errors), set the 'no way out' flag. * Use EIPV for testing whether an app can be killed (SIGBUS) rather than RIPV. According to docs, EIPV indicates that the error is related to the IP, while RIPV simply means the IP is valid to restart from. * Don't clear the MCi_STATUS registers until after the panic() path. This leaves the status bits set after the panic() so clever BIOSes can find them (and dumb BIOSes can do nothing). This patch also calls nonseekable_open() in mce_open (as suggested by akpm). Result: Tolerant levels behave almost identically to how they always have, but not it's well defined. There's a slightly higher chance of panic()ing when multiple errors happen (a good thing, IMHO). If you take an MBE and panic(), the error status bits are not cleared. Alternatives: None. Testing: I used software to inject correctable and uncorrectable errors. With tolerant = 3, the system usually survives. With tolerant = 2, the system usually panic()s (PCC) but not always. With tolerant = 1, the system always panic()s. When the system panic()s, the BIOS is able to detect that the cause of death was an MC4. I was not able to reproduce the case of a non-PCC error in userspace, with EIPV, with (tolerant < 3). That will be rare at best. Signed-off-by: Tim Hockin <thockin@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-21x86_64: remove unused variable maxcpusJan Beulich
.. and adjust documentation to properly reflect options that are x86-64 specific. Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-02[PATCH] x86-64: Dynamically adjust machine check intervalTim Hockin
Background: We've found that MCEs (specifically DRAM SBEs) tend to come in bunches, especially when we are trying really hard to stress the system out. The current MCE poller uses a static interval which does not care whether it has or has not found MCEs recently. Description: This patch makes the MCE poller adjust the polling interval dynamically. If we find an MCE, poll 2x faster (down to 10 ms). When we stop finding MCEs, poll 2x slower (up to check_interval seconds). The check_interval tunable becomes the max polling interval. The "Machine check events logged" printk() is rate limited to the check_interval, which should be identical behavior to the old functionality. Result: If you start to take a lot of correctable errors (not exceptions), you log them faster and more accurately (less chance of overflowing the MCA registers). If you don't take a lot of errors, you will see no change. Alternatives: I considered simply reducing the polling interval to 10 ms immediately and keeping it there as long as we continue to find errors. This felt a bit heavy handed, but does perform significantly better for the default check_interval of 5 minutes (we're using a few seconds when testing for DRAM errors). I could be convinced to go with this, if anyone felt it was not too aggressive. Testing: I used an error-injecting DIMM to create lots of correctable DRAM errors and verified that the polling interval accelerates. The printk() only happens once per check_interval seconds. Patch: This patch is against 2.6.21-rc7. Signed-Off-By: Tim Hockin <thockin@google.com> Signed-off-by: Andi Kleen <ak@suse.de>
2007-05-02[PATCH] x86-64: fake numa for cpusets documentDavid Rientjes
Create a document to explain how to use numa=fake in conjunction with cpusets for coarse memory resource management. An attempt to get more awareness and testing for this feature. Cc: Andi Kleen <ak@suse.de> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Paul Jackson <pj@sgi.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2007-05-02[PATCH] x86-64: fixed size remaining fake nodesDavid Rientjes
Extends the numa=fake x86_64 command-line option to split the remaining system memory into nodes of fixed size. Any leftover memory is allocated to a final node unless the command-line ends with a comma. For example: numa=fake=2*512,*128 gives two 512M nodes and the remaining system memory is split into nodes of 128M each. This is beneficial for systems where the exact size of RAM is unknown or not necessarily relevant, but the size of the remaining nodes to be allocated is known based on their capacity for resource management. Cc: Andi Kleen <ak@suse.de> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Paul Jackson <pj@sgi.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2007-05-02[PATCH] x86-64: split remaining fake nodes equallyDavid Rientjes
Extends the numa=fake x86_64 command-line option to split the remaining system memory into equal-sized nodes. For example: numa=fake=2*512,4* gives two 512M nodes and the remaining system memory is split into four approximately equal chunks. This is beneficial for systems where the exact size of RAM is unknown or not necessarily relevant, but the granularity with which nodes shall be allocated is known. Cc: Andi Kleen <ak@suse.de> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Paul Jackson <pj@sgi.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2007-05-02[PATCH] x86-64: configurable fake numa node sizesDavid Rientjes
Extends the numa=fake x86_64 command-line option to allow for configurable node sizes. These nodes can be used in conjunction with cpusets for coarse memory resource management. The old command-line option is still supported: numa=fake=32 gives 32 fake NUMA nodes, ignoring the NUMA setup of the actual machine. But now you may configure your system for the node sizes of your choice: numa=fake=2*512,1024,2*256 gives two 512M nodes, one 1024M node, two 256M nodes, and the rest of system memory to a sixth node. The existing hash function is maintained to support the various node sizes that are possible with this implementation. Each node of the same size receives roughly the same amount of available pages, regardless of any reserved memory with its address range. The total available pages on the system is calculated and divided by the number of equal nodes to allocate. These nodes are then dynamically allocated and their borders extended until such time as their number of available pages reaches the required size. Configurable node sizes are recommended when used in conjunction with cpusets for memory control because it eliminates the overhead associated with scanning the zonelists of many smaller full nodes on page_alloc(). Cc: Andi Kleen <ak@suse.de> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Paul Jackson <pj@sgi.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2007-04-24[PATCH] x86: Remove noreplacement optionAndi Kleen
noreplacement is dangerous on modern systems because it will not replace the context switch FNSAVE with SSE aware FXSAVE. But other places in the kernel still assume SSE and do FXSAVE and the CPU will then access FXSAVE information with FNSAVE and cause corruption. Easiest way to avoid this is to remove the option. It was mostly for paranoia reasons anyways and alternative()s have been stable for some time. Thanks to Jeremy F. for reporting and helping debug it. Signed-off-by: Andi Kleen <ak@suse.de>
2007-02-13[PATCH] x86-64: Allow to run a program when a machine check event is detectedAndi Kleen
When a machine check event is detected (including a AMD RevF threshold overflow event) allow to run a "trigger" program. This allows user space to react to such events sooner. The trigger is configured using a new trigger entry in the machinecheck sysfs interface. It is currently shared between all CPUs. I also fixed the AMD threshold handler to run the machine check polling code immediately to actually log any events that might have caused the threshold interrupt. Also added some documentation for the mce sysfs interface. Signed-off-by: Andi Kleen <ak@suse.de>
2007-02-13[PATCH] x86-64: cleanup Doc/x86_64/ filesRandy Dunlap
Fix typos. Lots of whitespace changes for readability and consistency. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andi Kleen <ak@suse.de>
2007-02-13[PATCH] x86-64: improved iommu documentationKarsten Weiss
- add SWIOTLB config help text - mention Documentation/x86_64/boot-options.txt in Documentation/kernel-parameters.txt - remove the duplication of the iommu kernel parameter documentation. - Better explanation of some of the iommu kernel parameter options. - "32MB<<order" instead of "32MB^order". - Mention the default "order" value. - list the four existing PCI-DMA mapping implementations of arch x86_64 - group the iommu= option keywords by PCI-DMA mapping implementation. - Distinguish iommu= option keywords from number arguments. - Explain the meaning of DAC and SAC. Signed-off-by: Karsten Weiss <knweiss@science-computing.de> Signed-off-by: Andi Kleen <ak@suse.de> Acked-by: Muli Ben-Yehuda <muli@il.ibm.com> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org>
2007-01-08Revert "[PATCH] x86-64: Try multiple timer variants in check_timer"Linus Torvalds
This reverts commit b026872601976f666bae77b609dc490d1834bf77, which has been linked to several problem reports with IO-APIC and the timer. Machines either don't boot because the timer doesn't happen, or we get double timer interrupts because we end up double-routing the timer irq through multiple interfaces. See for example http://lkml.org/lkml/2006/12/16/101 http://lkml.org/lkml/2007/1/3/9 http://bugzilla.kernel.org/show_bug.cgi?id=7789 about some of the discussion. Patches to fix this cleanup exist (and have been confirmed to work fine at least for some of the affected cases) and we'll revisit it for 2.6.21, but this late in the -rc series we're better off just reverting the incomplete commit that caused the problems. Suggested-by: Adrian Bunk <bunk@stusta.de> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Yinghai Lu <yinghai.lu@amd.com> Cc: Andrew Morton <akpm@osdl.org> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07[PATCH] Calgary: allow compiling Calgary in but not using it by defaultMuli Ben-Yehuda
This patch makes it possible to compile Calgary in but not use it by default. In this mode, use 'iommu=calgary' to activate it. Signed-off-by: Muli Ben-Yehuda <muli@il.ibm.com> Signed-off-by: Jon Mason <jdmason@kudzu.us> Signed-off-by: Andi Kleen <ak@suse.de>
2006-12-07[PATCH] x86-64: Try multiple timer variants in check_timerAndi Kleen
Instead of adding all kinds of more quirks try various timer routing variants in check_timer. In particular this tries to handle quirks from: - Nvidia NF2-4 reference BIOS: wrong timer override - Asus: Wrong timer override but no HPET table - ATI: require timer disabled in 8259 - Some boards: require timer enabled in 8259 We just try many of the the known variants in the hopefully right order in check_timer. Trying pin 0/2 on Nvidia suggested by Tim Hockin. TBD Experimental. Needs a lot of testing Signed-off-by: Andi Kleen <ak@suse.de>
2006-10-03Fix typos in Documentation/: 'Q'-'R'Matt LaPlante
This patch fixes typos in various Documentation txts. The patch addresses some words starting with the letters 'Q'-'R'. Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com> Acked-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-09-30[PATCH] Document iommu=panicAndi Kleen
Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-30[PATCH] Allow disabling DAC using command line optionsAndi Kleen
Might or might not work around some reported bugs on VIA systems. Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26[PATCH] Add stack documentation document from Keith OwensAndi Kleen
Describes the stack organization on x86-64. I changed it a bit and removed some obsolete information and the questions. Cc: kaos@sgi.com Signed-off-by: Andi Kleen <ak@suse.de>
2006-09-26[PATCH] Document backtracer selection optionsAndi Kleen
Signed-off-by: Andi Kleen <ak@suse.de>
2006-07-28[PATCH] x86_64: Document backtracer selection optionsAndi Kleen
Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] x86_64: Calgary IOMMU - Calgary specific bitsJon Mason
This patch hooks Calgary into the build, the x86-64 IOMMU initialization paths, and introduces the Calgary specific bits. The implementation draws inspiration from both PPC (which has support for the same chip but requires firmware support which we don't have on x86-64) and gart. Calgary is different from gart in that it support a translation table per PHB, as opposed to the single gart aperture. Changes from previous version: * Addition of boot-time disablement for bus-level translation/isolation (e.g, enable userspace DMA for things like X) * Usage of newer IOMMU abstraction functions Signed-off-by: Muli Ben-Yehuda <muli@il.ibm.com> Signed-off-by: Jon Mason <jdmason@us.ibm.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-09[PATCH] x86_64: Reserve SRAT hotadd memory on x86-64Andi Kleen
From: Keith Mannthey, Andi Kleen Implement memory hotadd without sparsemem. The memory in the SRAT hotadd area is just preserved instead and can be activated later. There are a few restrictions: - Only one continuous hotadd area allowed per node The main problem is dealing with the many buggy SRAT tables that are out there. The strategy here is to reject anything suspicious. Originally from Keith Mannthey, with several hacks and changes by AK and also contributions from Andrew Morton [ TBD: Problems pointed out by KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>: 1) Goto's rebuild_zonelist patch will not work if CONFIG_MEMORY_HOTPLUG=n. Rebuilding zonelist is necessary when the system has just memory < 4G at boot, and hot add memory > 4G. because x86_64 has DMA32, ZONE_NORAML is not included into zonelist at boot time if system doesn't have memory >4G at boot. [AK: should just force the higher zones at boot time when SRAT tells us] 2) zone and node's spanned_pages and present_pages are not incremented. They should be. For example, our server (ia64/Fujitsu PrimeQuest) can equip memory from 4G to 1T(maybe 2T in future), and SRAT will *always* say we have possible 1T +memory. (Microsoft requires "write all possible memory in SRAT") When we reserve memmap for possible 1T memory, Linux will not work well in +minimum 4G configuraion ;) [AK: needs limiting to 5-10% of max memory] ] Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-26[PATCH] x86_64: Better ATI timer fixAndi Kleen
The previous experiment for using apicmaintimer on ATI systems didn't work out very well. In particular laptops with C2/C3 support often don't let it tick during idle, which makes it useless. There were also some other bugs that made the apicmaintimer often not used at all. I tried some other experiments - running timer over RTC and some other things but they didn't really work well neither. I rechecked the specs now and it turns out this simple change is actually enough to avoid the double ticks on the ATI systems. We just turn off IRQ 0 in the 8254 and only route it directly using the IO-APIC. I tested it on a few ATI systems and it worked there. In fact it worked on all chipsets (NVidia, Intel, AMD, ATI) I tried it on. According to the ACPI spec routing should always work through the IO-APIC so I think it's the correct thing to do anyways (and most of the old gunk in check_timer should be thrown away for x86-64). But for 2.6.16 it's best to do a fairly minimal change: - Use the known to be working everywhere-but-ATI IRQ0 both over 8254 and IO-APIC setup everywhere - Except on ATI disable IRQ0 in the 8254 - Remove the code to select apicmaintimer on ATI chipsets - Add some boot options to allow to override this (just paranoia) In 2.6.17 I hope to switch the default over to this for everybody. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-04[PATCH] x86_64: Calibrate APIC timer using PM timerAndi Kleen
On some broken motherboards (at least one NForce3 based AMD64 laptop) the PIT timer runs at a incorrect frequency. This patch adds a new option "apicpmtimer" that allows to use the APIC timer and calibrate it using the PMTimer. It requires the earlier patch that allows to run the main timer from the APIC. Specifying apicpmtimer implies apicmaintimer. The option defaults to off for now. I tested it on a few systems and the resulting APIC timer frequencies were usually a bit off, but always <1%, which should be tolerable. TBD figure out heuristic to enable this automatically on the affected systems TBD perhaps do it on all NForce3s or using DMI? Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-04[PATCH] x86_64: Allow to run main time keeping from the local APIC interruptAndi Kleen
Another piece from the no-idle-tick patch. This can be enabled with the "apicmaintimer" option. This is mainly useful when the PIT/HPET interrupt is unreliable. Note there are some systems that are known to stop the APIC timer in C3. For those it will never work, but this case should be automatically detected. It also only works with PM timer right now. When HPET is used the way the main timer handler computes the delay doesn't work. It should be a bit more efficient because there is one less regular interrupt to process on the boot processor. Requires earlier bugfix from Venkatesh Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-15spelling: s/appropiate/appropriate/Adrian Bunk
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-01-11[PATCH] x86_64: Add documentation for CPU hotplug ACPI extensionAndi Kleen
Cc: len.brown@intel.com, ashok.ray@intel.com Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-11[PATCH] x86_64: Don't reserve hotplug CPUs by defaultAndi Kleen
Most users don't need it so no need to waste memory. This means an user has to specify the appropiate number of hotplug CPUs on the command line with additional_cpus=... or fix their BIOS to follow the convention in Documentation/x86-64/cpu-hotplug-spec Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-14[PATCH] x86_64: Remove CONFIG_CHECKING and add command line option for ↵Andi Kleen
pagefault tracing CONFIG_CHECKING covered some debugging code used in the early times of the port. But it wasn't even SMP safe for quite some time and the bugs it checked for seem to be gone. This patch removes all the code to verify GS at kernel entry. There haven't been any new bugs in this area for a long time. Previously it also covered the sysctl for the page fault tracing. That didn't make much sense because that code was unconditionally compiled in. I made that a boot option now because it is typically only useful at boot. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-14[PATCH] x86_64: Log machine checks from boot on Intel systemsAndi Kleen
The logging for boot errors was turned off because it was broken on some AMD systems. But give Intel EM64T systems a chance because they are supposed to be correct there. The advantage is that there is a chance to actually log uncorrected machine checks after the reset. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-14[PATCH] x86_64: New heuristics to find out hotpluggable CPUs.Andi Kleen
With a NR_CPUS==128 kernel with CPU hotplug enabled we would waste 4MB on per CPU data of all possible CPUs. The reason was that HOTPLUG always set up possible map to NR_CPUS cpus and then we need to allocate that much (each per CPU data is roughly ~32k now) The underlying problem is that ACPI didn't tell us how many hotplug CPUs the platform supports. So the old code just assumed all, which would lead to this memory wastage. This implements some new heuristics: - If the BIOS specified disabled CPUs in the ACPI/mptables assume they can be enabled later (this is bending the ACPI specification a bit, but seems like a obvious extension) - The user can overwrite it with a new additionals_cpus=NUM option - Otherwise use half of the available CPUs or 2, whatever is more. Cc: ashok.raj@intel.com Cc: len.brown@intel.com Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-14[PATCH] x86_64: Some clarifications for Documention/x86_64/mm.txtAndi Kleen
I got some questions on this, so just fix up the documentation. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-12[PATCH] x86-64: Add command line option to set machine check tolerance levelAndi Kleen
Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-07[PATCH] x86_64: ignore machine checks from boot timeAndi Kleen
Don't log machine check events left over from boot. Too many BIOSes leave bogus events in there. This unfortunately also makes it impossible to log events that caused a reboot. For people with non broken BIOS there is mce=bootlog Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-28[PATCH] x86_64: Some updates for boot-options.txtAndi Kleen
Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-20[PATCH] x86_64: Add option to disable timer checkAndi Kleen
This works around the too fast timer seen on some ATI boards. I don't feel confident enough about it yet to enable it by default, but give users the option. Patch and debugging from Christopher Allen Wing <wingc@engin.umich.edu>, with minor tweaks (renamed the option and documented it) Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!