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2006-02-01Merge git://git.kernel.org/pub/scm/linux/kernel/git/perex/alsaLinus Torvalds
2006-02-01Merge branch 'release' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6
2006-02-01[PATCH] Doc/kernel-doc: add more usage infoRandy Dunlap
- Add info that structs, unions, enums, and typedefs are supported. - Add doc about "private:" and "public:" tags for struct fields. - Fix some typos. - Remove some trailing whitespace. Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01[PATCH] RCU documentation fixes (January 2006 update)Paul E. McKenney
Updates to in-tree RCU documentation based on comments over the past few months. Signed-off-by: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01[PATCH] Direct Migration V9: migrate_pages() extensionChristoph Lameter
Add direct migration support with fall back to swap. Direct migration support on top of the swap based page migration facility. This allows the direct migration of anonymous pages and the migration of file backed pages by dropping the associated buffers (requires writeout). Fall back to swap out if necessary. The patch is based on lots of patches from the hotplug project but the code was restructured, documented and simplified as much as possible. Note that an additional patch that defines the migrate_page() method for filesystems is necessary in order to avoid writeback for anonymous and file backed pages. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Mike Kravetz <kravetz@us.ibm.com> Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01[PATCH] Reclaim slab during zone reclaimChristoph Lameter
If large amounts of zone memory are used by empty slabs then zone_reclaim becomes uneffective. This patch shakes the slab a bit. The problem with this patch is that the slab reclaim is not containable to a zone. Thus slab reclaim may affect the whole system and be extremely slow. This also means that we cannot determine how many pages were freed in this zone. Thus we need to go off node for at least one allocation. The functionality is disabled by default. We could modify the shrinkers to take a zone parameter but that would be quite invasive. Better ideas are welcome. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01[PATCH] Zone reclaim: Allow modification of zone reclaim behaviorChristoph Lameter
In some situations one may want zone_reclaim to behave differently. For example a process writing large amounts of memory will spew unto other nodes to cache the writes if many pages in a zone become dirty. This may impact the performance of processes running on other nodes. Allowing writes during reclaim puts a stop to that behavior and throttles the process by restricting the pages to the local zone. Similarly one may want to contain processes to local memory by enabling regular swap behavior during zone_reclaim. Off node memory allocation can then be controlled through memory policies and cpusets. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01[PATCH] zone_reclaim: configurable off node allocation period.Christoph Lameter
Currently the zone_reclaim code has a fixed window of 30 seconds of off node allocations should a local zone have no unused pagecache pages left. Reclaim will be attempted again after this timeout period to avoid repeated useless scans for memory. This is also useful to established sufficiently large off node allocation chunks to relieve the local node. It may be beneficial to adjust that time period for some special situations. For example if memory use was exceeding node capacity one may want to give up for longer periods of time. If memory spikes intermittendly then one may want to shorten the time period to reduce the number of off node allocations. This patch allows just that.... Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01[PATCH] powerpc: Add flattened device tree documentationDavid Gibson
The flattened device tree is the only supported way of booting ARCH=powerpc kernels on non Open Firmware machines. The documentation for the flattened tree format and contents has been discussed on mailing lists and lately has been living in the dtc git tree. Really, it ought to go in the kernel's Documentation directory for maximum visibility. Signed-off-by: David Gibson <dwg@au1.ibm.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01[PATCH] swsusp: use bytes as image size unitsRafael J. Wysocki
Make swsusp use bytes as the image size units, which is needed for future compatibility. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01[ALSA] fix typos in writing-an-alsa-driverGiuliano Pochini
Modules: Documentation Fixed typos in writing-an-alsa-driver document. Signed-off-by: Giuliano Pochini <pochini@shiny.it> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2006-02-01[ALSA] intel8x0 - Add MCP51 PCI IDTakashi Iwai
Modules: Documentation,Intel8x0 driver Added MCP51 PCI ID to intel8x0 driver. Also, updated the supported chips in documentation. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2006-01-31Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/pci-2.6Linus Torvalds
2006-01-31[PATCH] pci: Schedule removal of pci_module_initRichard Knutsson
Scheduled the removal of pci_module_init. Signed-off-by: Richard Knutsson <ricknu-0@student.ltu.se> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-31[PATCH] PCI: schedule PCI_LEGACY_PROC for removalAdrian Bunk
PCI_LEGACY_PROC is deprecated since 2.5.53 in favor of lspci(8). Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-31[PATCH] USB: drivers/usb/media/w9968cf.c: remove hooks for the vpp moduleAdrian Bunk
- the w9968cf-vpp module is not intended for inclusion into the kernel - the upstream w9968cf package shipping the w9968cf-vpp module suggests to simply replace the w9968cf module shipped with the kernel Therefore, there seems to be no good reason spending some bytes of kernel memory for hooks for the w9968cf-vpp module. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Luca Risolia <luca.risolia@studio.unibo.it> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-31[PATCH] USB: Add ET61X[12]51 Video4Linux2 driverLuca Risolia
This patch adds a Video4Linux2 driver giving support to ET61X151 and ET61X251 PC Camera Controllers made by Etoms Electronics. Signed-off-by: Luca Risolia <luca.risolia@studio.unibo.it> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-31[PATCH] USB: SN9C10x driver updatesLuca Risolia
SN9C10x driver updates: - Use kzalloc() instead of kmalloc() - Move some macro definitions from sn9c102.h to sn9c102_core.c - Use vfree() and vmalloc_32() instead of rvfree() and rvmalloc() - Fix mmap() sys call - Documentation updates Signed-off-by: Luca Risolia <luca.risolia@studio.unibo.it> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-31[PATCH] USB: SN9C10x driver updates and bugfixesLuca Risolia
SN9C10x driver updates and bugfixes. Changes: + new, - removed, * cleanup, @ bugfix: @ fix poll() @ Remove bad get_ctrl()'s * Reduce ioctl stack usage * Remove final ";" from some macro definitions * Better support for SN9C103 + Add sn9c102_write_regs() + Add 0x0c45/0x602d to the list of SN9C10x based devices + Add support for OV7630 image sensors + Provide support for the built-in microphone interface of the SN9C103 + Documentation updates + Add 0x0c45/0x602e to the list of SN9C10x based devices Signed-off-by: Luca Risolia <luca.risolia@studio.unibo.it> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-31[SCSI] aic7xxx: update documentationHannes Reinecke
This patch updates the documentation for aic7xxx and aic79xx with fixes from the adaptec driver. Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-01-29[SCSI] megaraid_sas: new template defined to represent each type of controllersSumant Patro
This patch defines a new template to represent each type of controllers (identified by the processor used). The template has members that is set with appropriate values during driver initialisation. This change is done to support new controllers with minimal change to existing code. In future, for a new controller support, a template will be declared and its members initialised appropriately. Signed-off-by: Sumant Patro <Sumant.Patro@lsil.com> Rejections fixed and Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-01-29[SCSI] megaraid_sas: cleanup queue command pathSumant Patro
This patch (originally submitted by Christoph Hellwig) removes code duplication in megasas_build_cmd. It also defines MEGASAS_IOC_FIRMWARE32 to allow 64 bit compiled applications to work. Signed-off-by: Sumant Patro <Sumant.Patro@lsil.com> Rejections fixed and Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-01-24[ACPI] merge 3549 4320 4485 4588 4980 5483 5651 acpica asus fops pnpacpi ↵Len Brown
branches into release Signed-off-by: Len Brown <len.brown@intel.com>
2006-01-18[PATCH] EDAC: core EDAC support codeAlan Cox
This is a subset of the bluesmoke project core code, stripped of the NMI work which isn't ready to merge and some of the "interesting" proc functionality that needs reworking or just has no place in kernel. It requires no core kernel changes except the added scrub functions already posted. The goal is to merge further functionality only after the core code is accepted and proven in the base kernel, and only at the point the upstream extras are really ready to merge. From: doug thompson <norsk5@xmission.com> This converts EDAC to sysfs and is the final chunk neccessary before EDAC has a stable user space API and can be considered for submission into the base kernel. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com> Signed-off-by: doug thompson <norsk5@xmission.com> Signed-off-by: Pavel Machek <pavel@suse.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-18[PATCH] Zone reclaim: proc overrideChristoph Lameter
proc support for zone reclaim This patch creates a proc entry /proc/sys/vm/zone_reclaim_mode that may be used to override the automatic determination of the zone reclaim made on bootup. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-16Merge branch 'for-linus' of git://brick.kernel.dk/data/git/linux-2.6-blockLinus Torvalds
2006-01-16Merge master.kernel.org:/pub/scm/linux/kernel/git/mchehab/v4l-dvbLinus Torvalds
2006-01-16[PATCH] fuse: update documentation for sysfsMiklos Szeredi
Add documentation for new attributes in sysfs. Also describe the filesystem. Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-16Merge branch 'master' of ↵Mauro Carvalho Chehab
ssh://master.kernel.org/pub/scm/linux/kernel/git/mchehab/v4l-dvb
2006-01-16barrier.txt got lost while the new barrier patchset was climbing upTejun Heo
the ladder to the mainline. Add it back. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Jens Axboe <axboe@suse.de>
2006-01-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivialLinus Torvalds
2006-01-15Merge ssh://master.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6Mauro Carvalho Chehab
2006-01-14[PATCH] When CONFIG_CC_OPTIMIZE_FOR_SIZE, allow gcc4 to control inliningIngo Molnar
If optimizing for size (CONFIG_CC_OPTIMIZE_FOR_SIZE), allow gcc4 compilers to decide what to inline and what not - instead of the kernel forcing gcc to inline all the time. This requires several places that require to be inlined to be marked as such, previous patches in this series do that. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-14[PATCH] Update kernel-parameters.txt IOSCHED to spell out 'anticipatory'Randy Dunlap
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-14[PATCH] nlm kernel-parameters updateRandy Dunlap
Add 2 lockd kernel parameters and spell 2 others correctly. Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Cc: Neil Brown <neilb@cse.unsw.edu.au> Cc: Olaf Kirch <okir@suse.de> Cc: <buraphalinuxserver@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-14[PATCH] Add tmpfs options for memory placement policiesRobin Holt
Anything that writes into a tmpfs filesystem is liable to disproportionately decrease the available memory on a particular node. Since there's no telling what sort of application (e.g. dd/cp/cat) might be dropping large files there, this lets the admin choose the appropriate default behavior for their site's situation. Introduce a tmpfs mount option which allows specifying a memory policy and a second option to specify the nodelist for that policy. With the default policy, tmpfs will behave as it does today. This patch adds support for preferred, bind, and interleave policies. The default policy will cause pages to be added to tmpfs files on the node which is doing the writing. Some jobs expect a single process to create and manage the tmpfs files. This results in a node which has a significantly reduced number of free pages. With this patch, the administrator can specify the policy and nodes for that policy where they would prefer allocations. This patch was originally written by Brent Casavant and Hugh Dickins. I added support for the bind and preferred policies and the mpol_nodelist mount option. Signed-off-by: Brent Casavant <bcasavan@sgi.com> Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Robin Holt <holt@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-15Fix "stuct", "strut", "struc" typosAlexey Dobriyan
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-01-15Documentation/hpet.txt typoRandy Dunlap
Fix a typo. Requested by Petr Vandrovec. Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-01-15spelling: s/appropiate/appropriate/Adrian Bunk
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-01-14Merge master.kernel.org:/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6Linus Torvalds
2006-01-14Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/spi-2.6Linus Torvalds
2006-01-14[PATCH] docs: update some updated code docsXose Vazquez Perez
Based on comments from Randy Dunlap on my previous commit 5b0ed2c64d8fdafb5fcfb3baabdd288628b1ff9b Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-13[PATCH] SPI: add spi_butterfly driverDavid Brownell
This adds a bitbanging parport based adaptor cable for AVR Butterfly, giving SPI links to its DataFlash chip and (eventually) firmware running in the card. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-13[PATCH] spi: misc fixesDavid Brownell
This collects some small SPI patches that seem to be missing from the MM tree: - spi_butterfly kbuild hooks got dropped somehow; this restores them - quick fix for a (theoretical?) m25p80_write() oops noted by Andrew - quick fix for a potential config-specific oops for mtd_dataflash() - minor doc tweaks Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-13[PATCH] SPI core tweaks, bugfixDavid Brownell
This includes various updates to the SPI core: - Fixes a driver model refcount bug in spi_unregister_master() paths. - The spi_master structures now have wrappers which help keep drivers from needing class-level get/put for device data or for refcounts. - Check for a few setup errors that would cause oopsing later. - Docs say more about memory management. Highlights the use of DMA-safe i/o buffers, and zero-initializing spi_message and such metadata. - Provide a simple alloc/free for spi_message and its spi_transfer; this is only one of the possible memory management policies. Nothing to break code that already works. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-13[PATCH] spi: add spi_driver to SPI frameworkDavid Brownell
This is a refresh of the "Simple SPI Framework" found in 2.6.15-rc3-mm1 which makes the following changes: * There's now a "struct spi_driver". This increase the footprint of the core a bit, since it now includes code to do what the driver core was previously handling directly. Documentation and comments were updated to match. * spi_alloc_master() now does class_device_initialize(), so it can at least be refcounted before spi_register_master(). To match, spi_register_master() switched over to class_device_add(). * States explicitly that after transfer errors, spi_devices will be deselected. We want fault recovery procedures to work the same for all controller drivers. * Minor tweaks: controller_data no longer points to readonly data; prevent some potential cast-from-null bugs with container_of calls; clarifies some existing kerneldoc, And a few small cleanups. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-13[PATCH] spi: simple SPI frameworkDavid Brownell
This is the core of a small SPI framework, implementing the model of a queue of messages which complete asynchronously (with thin synchronous wrappers on top). - It's still less than 2KB of ".text" (ARM). If there's got to be a mid-layer for something so simple, that's the right size budget. :) - The guts use board-specific SPI device tables to build the driver model tree. (Hardware probing is rarely an option.) - This version of Kconfig includes no drivers. At this writing there are two known master controller drivers (PXA/SSP, OMAP MicroWire) and three protocol drivers (CS8415a, ADS7846, DataFlash) with LKML mentions of other drivers in development. - No userspace API. There are several implementations to compare. Implement them like any other driver, and bind them with sysfs. The changes from last version posted to LKML (on 11-Nov-2005) are minor, and include: - One bugfix (removes a FIXME), with the visible effect of making device names be "spiB.C" where B is the bus number and C is the chipselect. - The "caller provides DMA mappings" mechanism now has kerneldoc, for DMA drivers that want to be fancy. - Hey, the framework init can be subsys_init. Even though board init logic fires earlier, at arch_init ... since the framework init is for driver support, and the board init support uses static init. - Various additional spec/doc clarifications based on discussions with other folk. It adds a brief "thank you" at the end, for folk who've helped nudge this framework into existence. As I've said before, I think that "protocol tweaking" is the main support that this driver framework will need to evolve. From: Mark Underwood <basicmark@yahoo.com> Update the SPI framework to remove a potential priority inversion case by reverting to kmalloc if the pre-allocated DMA-safe buffer isn't available. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-13V4L/DVB (3363): Add support for Samsung tuner TCPN 2121P30AHans Verkuil
- Add support for Samsung tuner TCPN 2121P30A, used in Hauppauge PVR-500 cards. Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2006-01-12[SCSI] aacraid: README updateMark Haverkamp
Received From Mark Salyzyn. Move the README from the driver directory to the Documentation directory. Updated the documentation, added descriptions for cards that were missing. Signed-off-by: Mark Haverkamp <markh@osdl.org> Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-01-12[PATCH] scheduler cache-hot-autodetectakpm@osdl.org
) From: Ingo Molnar <mingo@elte.hu> This is the latest version of the scheduler cache-hot-auto-tune patch. The first problem was that detection time scaled with O(N^2), which is unacceptable on larger SMP and NUMA systems. To solve this: - I've added a 'domain distance' function, which is used to cache measurement results. Each distance is only measured once. This means that e.g. on NUMA distances of 0, 1 and 2 might be measured, on HT distances 0 and 1, and on SMP distance 0 is measured. The code walks the domain tree to determine the distance, so it automatically follows whatever hierarchy an architecture sets up. This cuts down on the boot time significantly and removes the O(N^2) limit. The only assumption is that migration costs can be expressed as a function of domain distance - this covers the overwhelming majority of existing systems, and is a good guess even for more assymetric systems. [ People hacking systems that have assymetries that break this assumption (e.g. different CPU speeds) should experiment a bit with the cpu_distance() function. Adding a ->migration_distance factor to the domain structure would be one possible solution - but lets first see the problem systems, if they exist at all. Lets not overdesign. ] Another problem was that only a single cache-size was used for measuring the cost of migration, and most architectures didnt set that variable up. Furthermore, a single cache-size does not fit NUMA hierarchies with L3 caches and does not fit HT setups, where different CPUs will often have different 'effective cache sizes'. To solve this problem: - Instead of relying on a single cache-size provided by the platform and sticking to it, the code now auto-detects the 'effective migration cost' between two measured CPUs, via iterating through a wide range of cachesizes. The code searches for the maximum migration cost, which occurs when the working set of the test-workload falls just below the 'effective cache size'. I.e. real-life optimized search is done for the maximum migration cost, between two real CPUs. This, amongst other things, has the positive effect hat if e.g. two CPUs share a L2/L3 cache, a different (and accurate) migration cost will be found than between two CPUs on the same system that dont share any caches. (The reliable measurement of migration costs is tricky - see the source for details.) Furthermore i've added various boot-time options to override/tune migration behavior. Firstly, there's a blanket override for autodetection: migration_cost=1000,2000,3000 will override the depth 0/1/2 values with 1msec/2msec/3msec values. Secondly, there's a global factor that can be used to increase (or decrease) the autodetected values: migration_factor=120 will increase the autodetected values by 20%. This option is useful to tune things in a workload-dependent way - e.g. if a workload is cache-insensitive then CPU utilization can be maximized by specifying migration_factor=0. I've tested the autodetection code quite extensively on x86, on 3 P3/Xeon/2MB, and the autodetected values look pretty good: Dual Celeron (128K L2 cache): --------------------- migration cost matrix (max_cache_size: 131072, cpu: 467 MHz): --------------------- [00] [01] [00]: - 1.7(1) [01]: 1.7(1) - --------------------- cacheflush times [2]: 0.0 (0) 1.7 (1784008) --------------------- Here the slow memory subsystem dominates system performance, and even though caches are small, the migration cost is 1.7 msecs. Dual HT P4 (512K L2 cache): --------------------- migration cost matrix (max_cache_size: 524288, cpu: 2379 MHz): --------------------- [00] [01] [02] [03] [00]: - 0.4(1) 0.0(0) 0.4(1) [01]: 0.4(1) - 0.4(1) 0.0(0) [02]: 0.0(0) 0.4(1) - 0.4(1) [03]: 0.4(1) 0.0(0) 0.4(1) - --------------------- cacheflush times [2]: 0.0 (33900) 0.4 (448514) --------------------- Here it can be seen that there is no migration cost between two HT siblings (CPU#0/2 and CPU#1/3 are separate physical CPUs). A fast memory system makes inter-physical-CPU migration pretty cheap: 0.4 msecs. 8-way P3/Xeon [2MB L2 cache]: --------------------- migration cost matrix (max_cache_size: 2097152, cpu: 700 MHz): --------------------- [00] [01] [02] [03] [04] [05] [06] [07] [00]: - 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) [01]: 19.2(1) - 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) [02]: 19.2(1) 19.2(1) - 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) [03]: 19.2(1) 19.2(1) 19.2(1) - 19.2(1) 19.2(1) 19.2(1) 19.2(1) [04]: 19.2(1) 19.2(1) 19.2(1) 19.2(1) - 19.2(1) 19.2(1) 19.2(1) [05]: 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) - 19.2(1) 19.2(1) [06]: 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) - 19.2(1) [07]: 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) 19.2(1) - --------------------- cacheflush times [2]: 0.0 (0) 19.2 (19281756) --------------------- This one has huge caches and a relatively slow memory subsystem - so the migration cost is 19 msecs. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Ken Chen <kenneth.w.chen@intel.com> Cc: <wilder@us.ibm.com> Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>