From 016ddd9b5b315fe52ac6ba3167521f50b3868d34 Mon Sep 17 00:00:00 2001 From: Jiri Kosina Date: Mon, 18 Jan 2010 17:05:40 +0100 Subject: x86: Put 'nopat' in kernel-parameters Add missing 'nopat' boot option into Documentation/kernel-parameters.txt. Signed-off-by: Jiri Kosina LKML-Reference: Signed-off-by: Ingo Molnar --- Documentation/kernel-parameters.txt | 3 +++ 1 file changed, 3 insertions(+) (limited to 'Documentation/kernel-parameters.txt') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 736d45602886..5bf45c0ac749 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1729,6 +1729,9 @@ and is between 256 and 4096 characters. It is defined in the file nomfgpt [X86-32] Disable Multi-Function General Purpose Timer usage (for AMD Geode machines). + nopat [X86] Disable PAT (page attribute table extension of + pagetables) support. + norandmaps Don't use address space randomization. Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space -- cgit v1.2.2 From 0406ad336c066190770cbf350b552d608e43ed09 Mon Sep 17 00:00:00 2001 From: Alex Chiang Date: Wed, 20 Jan 2010 00:06:30 -0700 Subject: ACPI: processor: add kernel command line support for early _PDC eval Allow platforms not listed in DMI table to opt-in and evaluate _PDC early. Signed-off-by: Alex Chiang Signed-off-by: Len Brown --- Documentation/kernel-parameters.txt | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'Documentation/kernel-parameters.txt') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 736d45602886..826b6e148316 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -199,6 +199,10 @@ and is between 256 and 4096 characters. It is defined in the file acpi_display_output=video See above. + acpi_early_pdc_eval [HW,ACPI] Evaluate processor _PDC methods + early. Needed on some platforms to properly + initialize the EC. + acpi_irq_balance [HW,ACPI] ACPI will balance active IRQs default in APIC mode -- cgit v1.2.2 From d944d549aa86e08cba080396513234cf048fee1f Mon Sep 17 00:00:00 2001 From: Russell King Date: Sat, 20 Feb 2010 16:13:29 +0000 Subject: ARM: allow alignment fault mode to be configured at kernel boot Some glibc versions intentionally create lots of alignment faults in their gconv code, which if not fixed up, results in segfaults during boot. This can prevent systems booting properly. There is no clear hard-configurable default for this; the desired default depends on the nature of the userspace which is going to be booted. So, provide a way for the alignment fault handler to be configured via the kernel command line. Signed-off-by: Russell King --- Documentation/kernel-parameters.txt | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'Documentation/kernel-parameters.txt') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 826b6e148316..e7848a0d99eb 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -315,6 +315,11 @@ and is between 256 and 4096 characters. It is defined in the file aic79xx= [HW,SCSI] See Documentation/scsi/aic79xx.txt. + alignment= [KNL,ARM] + Allow the default userspace alignment fault handler + behaviour to be specified. Bit 0 enables warnings, + bit 1 enables fixups, and bit 2 sends a segfault. + amd_iommu= [HW,X86-84] Pass parameters to the AMD IOMMU driver in the system. Possible values are: -- cgit v1.2.2 From c7f486567c1d0acd2e4166c47069835b9f75e77b Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 17 Feb 2010 23:39:08 +0100 Subject: PCI PM: PCIe PME root port service driver PCIe native PME detection mechanism is based on interrupts generated by root ports or event collectors every time a PCIe device sends a PME message upstream. Once a PME message has been sent by an endpoint device and received by its root port (or event collector in the case of root complex integrated endpoints), the Requester ID from the message header is registered in the root port's Root Status register. At the same time, the PME Status bit of the Root Status register is set to indicate that there's a PME to handle. If PCIe PME interrupt is enabled for the root port, it generates an interrupt once the PME Status has been set. After receiving the interrupt, the kernel can identify the PCIe device that generated the PME using the Requester ID from the root port's Root Status register. [For details, see PCI Express Base Specification, Rev. 2.0.] Implement a driver for the PCIe PME root port service working in accordance with the above description. Based on a patch from Shaohua Li . Signed-off-by: Rafael J. Wysocki Signed-off-by: Jesse Barnes --- Documentation/kernel-parameters.txt | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'Documentation/kernel-parameters.txt') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index e7848a0d99eb..747a2c8f62f3 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1998,6 +1998,12 @@ and is between 256 and 4096 characters. It is defined in the file force Enable ASPM even on devices that claim not to support it. WARNING: Forcing ASPM on may cause system lockups. + pcie_pme= [PCIE,PM] Native PCIe PME signaling options: + off Do not use native PCIe PME signaling. + force Use native PCIe PME signaling even if the BIOS refuses + to allow the kernel to control the relevant PCIe config + registers. + pcmv= [HW,PCMCIA] BadgePAD 4 pd. [PARIDE] -- cgit v1.2.2 From c39fae1416d59fd565606793f090cebe3720d50d Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 17 Feb 2010 23:40:07 +0100 Subject: PCI PM: Make it possible to force using INTx for PCIe PME signaling Apparently, some machines may have problems with PCI run-time power management if MSIs are used for the native PCIe PME signaling. In particular, on the MSI Wind U-100 PCIe PME interrupts are not generated by a PCIe root port after a resume from suspend to RAM, if the system wake-up was triggered by a PME from the device attached to this port. [It doesn't help to free the interrupt on suspend and request it back on resume, even if that is done along with disabling the MSI and re-enabling it, respectively.] However, if INTx interrupts are used for this purpose on the same machine, everything works just fine. For this reason, add a kernel command line switch allowing one to request that MSIs be not used for the native PCIe PME signaling, introduce a DMI table allowing us to blacklist machines that need this switch to be set by default and put the MSI Wind U-100 into this table. Signed-off-by: Rafael J. Wysocki Signed-off-by: Jesse Barnes --- Documentation/kernel-parameters.txt | 2 ++ 1 file changed, 2 insertions(+) (limited to 'Documentation/kernel-parameters.txt') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 747a2c8f62f3..516225a864f9 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2003,6 +2003,8 @@ and is between 256 and 4096 characters. It is defined in the file force Use native PCIe PME signaling even if the BIOS refuses to allow the kernel to control the relevant PCIe config registers. + nomsi Do not use MSI for native PCIe PME signaling (this makes + all PCIe root ports use INTx for everything). pcmv= [HW,PCMCIA] BadgePAD 4 -- cgit v1.2.2 From 7bc5e3f2be32ae6fb0c74cd0f707f986b3a01a26 Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Tue, 23 Feb 2010 10:24:41 -0700 Subject: x86/PCI: use host bridge _CRS info by default on 2008 and newer machines The main benefit of using ACPI host bridge window information is that we can do better resource allocation in systems with multiple host bridges, e.g., http://bugzilla.kernel.org/show_bug.cgi?id=14183 Sometimes we need _CRS information even if we only have one host bridge, e.g., https://bugs.launchpad.net/ubuntu/+source/linux/+bug/341681 Most of these systems are relatively new, so this patch turns on "pci=use_crs" only on machines with a BIOS date of 2008 or newer. Signed-off-by: Bjorn Helgaas Signed-off-by: Jesse Barnes --- Documentation/kernel-parameters.txt | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'Documentation/kernel-parameters.txt') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 516225a864f9..3e69c1c4f508 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1948,8 +1948,12 @@ and is between 256 and 4096 characters. It is defined in the file IRQ routing is enabled. noacpi [X86] Do not use ACPI for IRQ routing or for PCI scanning. - use_crs [X86] Use _CRS for PCI resource - allocation. + use_crs [X86] Use PCI host bridge window information + from ACPI. On BIOSes from 2008 or later, this + is enabled by default. If you need to use this, + please report a bug. + nocrs [X86] Ignore PCI host bridge windows from ACPI. + If you need to use this, please report a bug. routeirq Do IRQ routing for all PCI devices. This is normally done in pci_enable_device(), so this option is a temporary workaround -- cgit v1.2.2 From 14315592009c17035cac81f4954d5a1f4d71e489 Mon Sep 17 00:00:00 2001 From: Ian Campbell Date: Wed, 17 Feb 2010 10:38:10 +0000 Subject: x86, mm: Allow highmem user page tables to be disabled at boot time Distros generally (I looked at Debian, RHEL5 and SLES11) seem to enable CONFIG_HIGHPTE for any x86 configuration which has highmem enabled. This means that the overhead applies even to machines which have a fairly modest amount of high memory and which therefore do not really benefit from allocating PTEs in high memory but still pay the price of the additional mapping operations. Running kernbench on a 4G box I found that with CONFIG_HIGHPTE=y but no actual highptes being allocated there was a reduction in system time used from 59.737s to 55.9s. With CONFIG_HIGHPTE=y and highmem PTEs being allocated: Average Optimal load -j 4 Run (std deviation): Elapsed Time 175.396 (0.238914) User Time 515.983 (5.85019) System Time 59.737 (1.26727) Percent CPU 263.8 (71.6796) Context Switches 39989.7 (4672.64) Sleeps 42617.7 (246.307) With CONFIG_HIGHPTE=y but with no highmem PTEs being allocated: Average Optimal load -j 4 Run (std deviation): Elapsed Time 174.278 (0.831968) User Time 515.659 (6.07012) System Time 55.9 (1.07799) Percent CPU 263.8 (71.266) Context Switches 39929.6 (4485.13) Sleeps 42583.7 (373.039) This patch allows the user to control the allocation of PTEs in highmem from the command line ("userpte=nohigh") but retains the status-quo as the default. It is possible that some simple heuristic could be developed which allows auto-tuning of this option however I don't have a sufficiently large machine available to me to perform any particularly meaningful experiments. We could probably handwave up an argument for a threshold at 16G of total RAM. Assuming 768M of lowmem we have 196608 potential lowmem PTE pages. Each page can map 2M of RAM in a PAE-enabled configuration, meaning a maximum of 384G of RAM could potentially be mapped using lowmem PTEs. Even allowing generous factor of 10 to account for other required lowmem allocations, generous slop to account for page sharing (which reduces the total amount of RAM mappable by a given number of PT pages) and other innacuracies in the estimations it would seem that even a 32G machine would not have a particularly pressing need for highmem PTEs. I think 32G could be considered to be at the upper bound of what might be sensible on a 32 bit machine (although I think in practice 64G is still supported). It's seems questionable if HIGHPTE is even a win for any amount of RAM you would sensibly run a 32 bit kernel on rather than going 64 bit. Signed-off-by: Ian Campbell LKML-Reference: <1266403090-20162-1-git-send-email-ian.campbell@citrix.com> Signed-off-by: H. Peter Anvin --- Documentation/kernel-parameters.txt | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'Documentation/kernel-parameters.txt') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 736d45602886..67c69ffe7b7f 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2694,6 +2694,13 @@ and is between 256 and 4096 characters. It is defined in the file medium is write-protected). Example: quirks=0419:aaf5:rl,0421:0433:rc + userpte= + [X86] Flags controlling user PTE allocations. + + nohigh = do not allocate PTE pages in + HIGHMEM regardless of setting + of CONFIG_HIGHPTE. + vdso= [X86,SH] vdso=2: enable compat VDSO (default with COMPAT_VDSO) vdso=1: enable VDSO (default) -- cgit v1.2.2