Searched hist:"63692 df1" (Results 1 – 2 of 2) sorted by relevance
| /openbmc/linux/Documentation/ABI/testing/ |
| H A D | sysfs-bus-pci | 63692df1 Thu Oct 23 13:22:12 CDT 2014 Prarit Bhargava <prarit@redhat.com> PCI: Allow numa_node override via sysfs
NUMA systems with ACPI normally describe the physical topology via _PXM
methods. But many BIOSes don't implement _PXM, which leaves the kernel
with no way to discover the device topology, which reduces performance
because we can't put memory and processes close to the device.
The NUMA node of a PCI device is already exported in the sysfs "numa_node"
file. Make that file writable so users can workaround the lack of _PXM
methods in the BIOS. For example:
echo 3 > /sys/devices/pci0000:ff/0000:03:1f.3/numa_node
sets the node for PCI device 0000:03:1f.3.
Writing the file emits a FW_BUG warning to encourage users to request
firmware updates. It also taints the kernel with TAINT_FIRMWARE_WORKAROUND
because overriding the node incorrectly can cause performance issues.
[bhelgaas: changelog, documentation text]
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Myron Stowe <mstowe@redhat.com>
CC: Alexander Ducyk <alexander.h.duyck@redhat.com>
CC: Jiang Liu <jiang.liu@linux.intel.com>
63692df1 Thu Oct 23 13:22:12 CDT 2014 Prarit Bhargava <prarit@redhat.com> PCI: Allow numa_node override via sysfs
NUMA systems with ACPI normally describe the physical topology via _PXM
methods. But many BIOSes don't implement _PXM, which leaves the kernel
with no way to discover the device topology, which reduces performance
because we can't put memory and processes close to the device.
The NUMA node of a PCI device is already exported in the sysfs "numa_node"
file. Make that file writable so users can workaround the lack of _PXM
methods in the BIOS. For example:
echo 3 > /sys/devices/pci0000:ff/0000:03:1f.3/numa_node
sets the node for PCI device 0000:03:1f.3.
Writing the file emits a FW_BUG warning to encourage users to request
firmware updates. It also taints the kernel with TAINT_FIRMWARE_WORKAROUND
because overriding the node incorrectly can cause performance issues.
[bhelgaas: changelog, documentation text]
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Myron Stowe <mstowe@redhat.com>
CC: Alexander Ducyk <alexander.h.duyck@redhat.com>
CC: Jiang Liu <jiang.liu@linux.intel.com>
|
| /openbmc/linux/drivers/pci/ |
| H A D | pci-sysfs.c | 63692df1 Thu Oct 23 13:22:12 CDT 2014 Prarit Bhargava <prarit@redhat.com> PCI: Allow numa_node override via sysfs
NUMA systems with ACPI normally describe the physical topology via _PXM
methods. But many BIOSes don't implement _PXM, which leaves the kernel
with no way to discover the device topology, which reduces performance
because we can't put memory and processes close to the device.
The NUMA node of a PCI device is already exported in the sysfs "numa_node"
file. Make that file writable so users can workaround the lack of _PXM
methods in the BIOS. For example:
echo 3 > /sys/devices/pci0000:ff/0000:03:1f.3/numa_node
sets the node for PCI device 0000:03:1f.3.
Writing the file emits a FW_BUG warning to encourage users to request
firmware updates. It also taints the kernel with TAINT_FIRMWARE_WORKAROUND
because overriding the node incorrectly can cause performance issues.
[bhelgaas: changelog, documentation text]
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Myron Stowe <mstowe@redhat.com>
CC: Alexander Ducyk <alexander.h.duyck@redhat.com>
CC: Jiang Liu <jiang.liu@linux.intel.com>
63692df1 Thu Oct 23 13:22:12 CDT 2014 Prarit Bhargava <prarit@redhat.com> PCI: Allow numa_node override via sysfs
NUMA systems with ACPI normally describe the physical topology via _PXM
methods. But many BIOSes don't implement _PXM, which leaves the kernel
with no way to discover the device topology, which reduces performance
because we can't put memory and processes close to the device.
The NUMA node of a PCI device is already exported in the sysfs "numa_node"
file. Make that file writable so users can workaround the lack of _PXM
methods in the BIOS. For example:
echo 3 > /sys/devices/pci0000:ff/0000:03:1f.3/numa_node
sets the node for PCI device 0000:03:1f.3.
Writing the file emits a FW_BUG warning to encourage users to request
firmware updates. It also taints the kernel with TAINT_FIRMWARE_WORKAROUND
because overriding the node incorrectly can cause performance issues.
[bhelgaas: changelog, documentation text]
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Myron Stowe <mstowe@redhat.com>
CC: Alexander Ducyk <alexander.h.duyck@redhat.com>
CC: Jiang Liu <jiang.liu@linux.intel.com>
|