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* Merge branch 'linus' into core/percpuIngo Molnar2009-01-271-94/+100
|\ | | | | | | | | Conflicts: arch/x86/kernel/setup_percpu.c
| * Merge git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-fixesLinus Torvalds2009-01-261-7/+0
| |\ | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-fixes: kbuild: fix kbuild.txt typos kbuild: print usage with no arguments in scripts/config Revert "kbuild: strip generated symbols from *.ko"
| | * Revert "kbuild: strip generated symbols from *.ko"Sam Ravnborg2009-01-141-7/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit ad7a953c522ceb496611d127e51e278bfe0ff483. And commit: ("allow stripping of generated symbols under CONFIG_KALLSYMS_ALL") 9bb482476c6c9d1ae033306440c51ceac93ea80c These stripping patches has caused a set of issues: 1) People have reported compatibility issues with binutils due to lack of support for `--strip-unneeded-symbols' with objcopy 2.15.92.0.2 Reported by: Wenji 2) ccache and distcc no longer works as expeced Reported by: Ted, Roland, + others 3) The installed modules increased a lot in size Reported by: Ted, Davej + others Reported-by: Wenji Huang <wenji.huang@oracle.com> Reported-by: "Theodore Ts'o" <tytso@mit.edu> Reported-by: Dave Jones <davej@redhat.com> Reported-by: Roland McGrath <roland@redhat.com> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
| * | Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6Linus Torvalds2009-01-261-0/+8
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (92 commits) gianfar: Revive VLAN support vlan: Export symbols as non GPL symbols. bnx2x: tx_has_work should not wait for FW netxen: reduce memory footprint netxen: fix vlan tso/checksum offload net: Fix linux/if_frad.h's suitability for userspace. net: Move config NET_NS to from net/Kconfig to init/Kconfig isdn: Fix missing ifdef in isdn_ppp networking: document "nc" in addition to "netcat" in netconsole.txt e1000e: workaround hw errata af_key: initialize xfrm encap_oa virtio_net: Fix MAX_PACKET_LEN to support 802.1Q VLANs lcs: fix compilation for !CONFIG_IP_MULTICAST rtl8187: Add termination packet to prevent stall iwlwifi: fix rs_get_rate WARN_ON() p54usb: fix packet loss with first generation devices sctp: Fix another socket race during accept/peeloff sctp: Properly timestamp outgoing data chunks for rtx purposes sctp: Correctly start rtx timer on new packet transmissions. sctp: Fix crc32c calculations on big-endian arhes. ...
| | * | net: Move config NET_NS to from net/Kconfig to init/KconfigMatt Helsley2009-01-261-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make NET_NS available underneath the generic Namespaces config option since all of the other namespace options are there. Signed-off-by: Matt Helsley <matthltc@us.ibm.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | Merge branch 'core/debugobjects' into core/urgentThomas Gleixner2009-01-221-33/+32
| |\ \ \ | | |/ /
| * | | rcu: move Kconfig menuMike Travis2009-01-151-87/+92
| | |/ | |/| | | | | | | | | | | | | | | | | | | | | | Move RCU Kconfig options from top-level menu to an "RCU Subsystem" menu under the "General Setup" menu. Signed-off-by: Mike Travis <travis@sgi.com> Tested-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | Merge branch 'x86/mm' into core/percpuIngo Molnar2009-01-211-33/+32
|\ \ \ | | |/ | |/| | | | | | | Conflicts: arch/x86/mm/fault.c
| * | cgroups: consolidate cgroup documentsLi Zefan2009-01-151-5/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move Documentation/cpusets.txt and Documentation/controllers/* to Documentation/cgroups/ Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | cgroups: clean up KconfigLi Zefan2009-01-151-28/+28
| |/ | | | | | | | | | | | | | | | | | | | | | | | | - move CONFIG_PROC_PID_CPUSET into cgroup menu - move MM_OWNER to the bottom for better menu indent - fix typos - use tabs not spaces Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Paul Menage <menage@google.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge branch 'core/percpu' into stackprotectorIngo Molnar2009-01-186-122/+154
|\ \ | |/ | | | | | | | | | | | | | | | | Conflicts: arch/x86/include/asm/pda.h arch/x86/include/asm/system.h Also, moved include/asm-x86/stackprotector.h to arch/x86/include/asm. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * Merge git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-linusLinus Torvalds2009-01-091-0/+14
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-linus: MAINTAINERS: squashfs entry Squashfs: documentation Squashfs: initrd support Squashfs: Kconfig entry Squashfs: Makefiles Squashfs: header files Squashfs: block operations Squashfs: cache operations Squashfs: uid/gid lookup operations Squashfs: fragment block operations Squashfs: export operations Squashfs: super block operations Squashfs: symlink operations Squashfs: regular file operations Squashfs: directory readdir operations Squashfs: directory lookup operations Squashfs: inode operations
| | * Squashfs: initrd supportPhillip Lougher2009-01-051-0/+14
| | | | | | | | | | | | Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
| * | Merge git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-nommuLinus Torvalds2009-01-091-0/+1
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-nommu: NOMMU: Support XIP on initramfs NOMMU: Teach kobjsize() about VMA regions. FLAT: Don't attempt to expand the userspace stack to fill the space allocated FDPIC: Don't attempt to expand the userspace stack to fill the space allocated NOMMU: Improve procfs output using per-MM VMAs NOMMU: Make mmap allocation page trimming behaviour configurable. NOMMU: Make VMAs per MM as for MMU-mode linux NOMMU: Delete askedalloc and realalloc variables NOMMU: Rename ARM's struct vm_region NOMMU: Fix cleanup handling in ramfs_nommu_get_umapped_area()
| | * | NOMMU: Support XIP on initramfsDavid Howells2009-01-081-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Support XIP on files unpacked from the initramfs image on NOMMU systems. This simply requires the length of the file to be preset so that the ramfs fs can attempt to garner sufficient contiguous storage to store the file (NOMMU mmap can only map contiguous RAM). All the other bits to do XIP on initramfs files are present: (1) ramfs's truncate attempts to allocate a contiguous run of pages when a file is truncated upwards from nothing. (2) ramfs sets BDI on its files to indicate direct mapping is possible, and that its files can be mapped for read, write and exec. (3) NOMMU mmap() will use the above bits to determine that it can do XIP. Possibly this needs better controls, because it will _always_ try and do XIP. One disadvantage of this very simplistic approach is that sufficient space will be allocated to store the whole file, and not just the bit that would be XIP'd. To deal with this, though, the initramfs unpacker would have to be able to parse the file contents. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Paul Mundt <lethal@linux-sh.org>
| * | | memcg: mem+swap controller KconfigKAMEZAWA Hiroyuki2009-01-081-0/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Config and control variable for mem+swap controller. This patch adds CONFIG_CGROUP_MEM_RES_CTLR_SWAP (memory resource controller swap extension.) For accounting swap, it's obvious that we have to use additional memory to remember "who uses swap". This adds more overhead. So, it's better to offer "choice" to users. This patch adds 2 choices. This patch adds 2 parameters to enable swap extension or not. - CONFIG - boot option Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | memcg: fix a typo in KconfigLi Zefan2009-01-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | s/contoller/controller/ Signed-of-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | cgroups: make cgroup config a submenuKAMEZAWA Hiroyuki2009-01-081-56/+67
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Making CGROUP related configs be a sub-menu. This patch make CGROUP related configs be a sub-menu and makes 1st level configs of "General Setup" shorter. including following additional changes - add help comment about CGROUPS and GROUP_SCHED. - moved MM_OWNER config to the bottom. (for good indent in menuconfig) Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | Merge git://git.kernel.org/pub/scm/linux/kernel/git/arjan/linux-2.6-asyncLinus Torvalds2009-01-072-1/+6
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/arjan/linux-2.6-async: async: don't do the initcall stuff post boot bootchart: improve output based on Dave Jones' feedback async: make the final inode deletion an asynchronous event fastboot: Make libata initialization even more async fastboot: make the libata port scan asynchronous fastboot: make scsi probes asynchronous async: Asynchronous function calls to speed up kernel boot
| | * | async: Asynchronous function calls to speed up kernel bootArjan van de Ven2009-01-072-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Right now, most of the kernel boot is strictly synchronous, such that various hardware delays are done sequentially. In order to make the kernel boot faster, this patch introduces infrastructure to allow doing some of the initialization steps asynchronously, which will hide significant portions of the hardware delays in practice. In order to not change device order and other similar observables, this patch does NOT do full parallel initialization. Rather, it operates more in the way an out of order CPU does; the work may be done out of order and asynchronous, but the observable effects (instruction retiring for the CPU) are still done in the original sequence. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
| * | | Merge branch 'for-linus' of ↵Linus Torvalds2009-01-071-1/+2
| |\ \ \ | | |/ / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (24 commits) trivial: chack -> check typo fix in main Makefile trivial: Add a space (and a comma) to a printk in 8250 driver trivial: Fix misspelling of "firmware" in docs for ncr53c8xx/sym53c8xx trivial: Fix misspelling of "firmware" in powerpc Makefile trivial: Fix misspelling of "firmware" in usb.c trivial: Fix misspelling of "firmware" in qla1280.c trivial: Fix misspelling of "firmware" in a100u2w.c trivial: Fix misspelling of "firmware" in megaraid.c trivial: Fix misspelling of "firmware" in ql4_mbx.c trivial: Fix misspelling of "firmware" in acpi_memhotplug.c trivial: Fix misspelling of "firmware" in ipw2100.c trivial: Fix misspelling of "firmware" in atmel.c trivial: Fix misspelled firmware in Kconfig trivial: fix an -> a typos in documentation and comments trivial: fix then -> than typos in comments and documentation trivial: update Jesper Juhl CREDITS entry with new email trivial: fix singal -> signal typo trivial: Fix incorrect use of "loose" in event.c trivial: printk: fix indentation of new_text_line declaration trivial: rtc-stk17ta8: fix sparse warning ...
| | * | trivial: add missing printk loglevel in start_kernelRon Lee2009-01-061-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Add missing printk loglevel in start_kernel Signed-off-by: Ron Lee <ron@debian.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
| * | | Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6Linus Torvalds2009-01-061-17/+27
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: (60 commits) uio: make uio_info's name and version const UIO: Documentation for UIO ioport info handling UIO: Pass information about ioports to userspace (V2) UIO: uio_pdrv_genirq: allow custom irq_flags UIO: use pci_ioremap_bar() in drivers/uio arm: struct device - replace bus_id with dev_name(), dev_set_name() libata: struct device - replace bus_id with dev_name(), dev_set_name() avr: struct device - replace bus_id with dev_name(), dev_set_name() block: struct device - replace bus_id with dev_name(), dev_set_name() chris: struct device - replace bus_id with dev_name(), dev_set_name() dmi: struct device - replace bus_id with dev_name(), dev_set_name() gadget: struct device - replace bus_id with dev_name(), dev_set_name() gpio: struct device - replace bus_id with dev_name(), dev_set_name() gpu: struct device - replace bus_id with dev_name(), dev_set_name() hwmon: struct device - replace bus_id with dev_name(), dev_set_name() i2o: struct device - replace bus_id with dev_name(), dev_set_name() IA64: struct device - replace bus_id with dev_name(), dev_set_name() i7300_idle: struct device - replace bus_id with dev_name(), dev_set_name() infiniband: struct device - replace bus_id with dev_name(), dev_set_name() ISDN: struct device - replace bus_id with dev_name(), dev_set_name() ...
| | * | | sysfs: clarify SYSFS_DEPRECATED help textKay Sievers2009-01-061-17/+27
| | |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This should make the help text of SYSFS_DEPRECATED more clear, that this is _not_ about (what some people think it is) suppressing a few symlinks and variables, but a different sysfs _layout_ with new features. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * | | init/main.c: mark late_time_init as __initdataJan Beulich2009-01-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | autodetect_raid: add missing __init markingMike Frysinger2009-01-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The function autodetect_raid is only used by __init functions, and it refers to __initdata, so it needs __init markings. Fixes this error: The function autodetect_raid() references the variable __initdata raid_noautodetect. This is often because autodetect_raid lacks a __initdata annotation or the annotation of raid_noautodetect is wrong. Signed-off-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | Remove remaining unwinder codeAlexey Dobriyan2009-01-061-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Gabor Gombas <gombasg@sztaki.hu> Cc: Jan Beulich <jbeulich@novell.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ingo Molnar <mingo@elte.hu>, Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | do_mounts: add device info to mount messageMarton Balint2009-01-061-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the past, I used the root=... command line parameter to specify the root filesystem to the kernel. Now it seems that specifying it is not necessary. The kernel detects the root filesystem even if the kernel command line is empty. My root fs is on a raid1 device by the way, and I am not using initrd for the boot process. If the kernel detects the root filesystem somehow, I think it should print out the result of this detection, otherwise I will not know which device has the root filesystem. Or is there an easy way to get this information on a running system? I had a quick look at the /proc and /sys filesystems, but haven't found anything useful there. Signed-off-by: Marton Balint <cus@fazekas.hu> Cc: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | init: properly placing noinline keywordRakib Mullick2009-01-061-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | checkpatch warns about 'static void noinline'. It wants `static noinline void'. Both are permissible, but the kernel consistently uses `static inline' and `static noinline', and consistency is good. Hence let's keep the checkpatch warning and fix up this code site. [akpm@linux-foundation.org: rewrote changelog] Signed-off-by: Md.Rakib H. Mullick <rakib.mullick@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | shmem: unify regular and tiny shmemMatt Mackall2009-01-061-4/+0
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | tiny-shmem shares most of its 130 lines of code with shmem and tends to break when particular bits of shmem get modified. Unifying saves code and makes keeping these two in sync much easier. before: 14367 392 24 14783 39bf mm/shmem.o 396 72 8 476 1dc mm/tiny-shmem.o after: 14367 392 24 14783 39bf mm/shmem.o 412 72 8 492 1ec mm/shmem.o tiny Signed-off-by: Matt Mackall <mpm@selenic.com> Acked-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | remove CONFIG_KMODJohannes Berg2009-01-051-6/+0
| |/ | | | | | | | | | | | | Now that nothing depends on it any more, remove CONFIG_KMOD. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
| * Merge branch 'cpus4096-for-linus-3' of ↵Linus Torvalds2009-01-031-9/+4
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'cpus4096-for-linus-3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (77 commits) x86: setup_per_cpu_areas() cleanup cpumask: fix compile error when CONFIG_NR_CPUS is not defined cpumask: use alloc_cpumask_var_node where appropriate cpumask: convert shared_cpu_map in acpi_processor* structs to cpumask_var_t x86: use cpumask_var_t in acpi/boot.c x86: cleanup some remaining usages of NR_CPUS where s/b nr_cpu_ids sched: put back some stack hog changes that were undone in kernel/sched.c x86: enable cpus display of kernel_max and offlined cpus ia64: cpumask fix for is_affinity_mask_valid() cpumask: convert RCU implementations, fix xtensa: define __fls mn10300: define __fls m32r: define __fls h8300: define __fls frv: define __fls cris: define __fls cpumask: CONFIG_DISABLE_OBSOLETE_CPUMASK_FUNCTIONS cpumask: zero extra bits in alloc_cpumask_var_node cpumask: replace for_each_cpu_mask_nr with for_each_cpu in kernel/time/ cpumask: convert mm/ ...
| | * cpumask: Use find_last_bit()Rusty Russell2009-01-011-6/+1
| | | | | | | | | | | | | | | | | | | | | | | | Impact: cleanup There's one obvious place to use it: to find the highest possible cpu. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
| | * cpumask: Use accessors code in coreRusty Russell2009-01-011-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: use new API cpu_*_map are going away in favour of cpu_*_mask, but const pointers. So we have accessors where we really do want to frob them. Archs will also need the (trivial) conversion before we can finally remove cpu_*_map. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Mike Travis <travis@sgi.com>
| | * Merge branch 'master' of ↵Rusty Russell2008-12-312-3/+94
| | |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 Conflicts: arch/x86/kernel/io_apic.c
| | * \ Merge branch 'master' of ↵Rusty Russell2008-12-302-15/+29
| | |\ \ | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
| * | \ \ Merge branch 'cpus4096-for-linus-2' of ↵Linus Torvalds2009-01-021-0/+9
| |\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'cpus4096-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (66 commits) x86: export vector_used_by_percpu_irq x86: use logical apicid in x2apic_cluster's x2apic_cpu_mask_to_apicid_and() sched: nominate preferred wakeup cpu, fix x86: fix lguest used_vectors breakage, -v2 x86: fix warning in arch/x86/kernel/io_apic.c sched: fix warning in kernel/sched.c sched: move test_sd_parent() to an SMP section of sched.h sched: add SD_BALANCE_NEWIDLE at MC and CPU level for sched_mc>0 sched: activate active load balancing in new idle cpus sched: bias task wakeups to preferred semi-idle packages sched: nominate preferred wakeup cpu sched: favour lower logical cpu number for sched_mc balance sched: framework for sched_mc/smt_power_savings=N sched: convert BALANCE_FOR_xx_POWER to inline functions x86: use possible_cpus=NUM to extend the possible cpus allowed x86: fix cpu_mask_to_apicid_and to include cpu_online_mask x86: update io_apic.c to the new cpumask code x86: Introduce topology_core_cpumask()/topology_thread_cpumask() x86: xen: use smp_call_function_many() x86: use work_on_cpu in x86/kernel/cpu/mcheck/mce_amd_64.c ... Fixed up trivial conflict in kernel/time/tick-sched.c manually
| | * \ \ \ Merge ../linux-2.6-x86Rusty Russell2008-12-132-15/+32
| | |\ \ \ \ | | | |/ / / | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: arch/x86/kernel/io_apic.c kernel/sched.c kernel/sched_stats.h
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| | | *---. \ \ Merge branches 'irq/sparseirq', 'x86/quirks' and 'x86/reboot' into cpus4096Ingo Molnar2008-12-121-0/+11
| | | |\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We merge the irq/sparseirq, x86/quirks and x86/reboot trees into the cpus4096 tree because the io-apic changes in the sparseirq change conflict with the cpumask changes in the cpumask tree, and we want to resolve those.
| | * | | | | | | cpumask: centralize cpu_online_map and cpu_possible_mapRusty Russell2008-12-131-0/+9
| | | |_|/ / / / | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: cleanup Each SMP arch defines these themselves. Move them to a central location. Twists: 1) Some archs (m32, parisc, s390) set possible_map to all 1, so we add a CONFIG_INIT_ALL_POSSIBLE for this rather than break them. 2) mips and sparc32 '#define cpu_possible_map phys_cpu_present_map'. Those archs simply have phys_cpu_present_map replaced everywhere. 3) Alpha defined cpu_possible_map to cpu_present_map; this is tricky so I just manipulate them both in sync. 4) IA64, cris and m32r have gratuitous 'extern cpumask_t cpu_possible_map' declarations. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Reviewed-by: Grant Grundler <grundler@parisc-linux.org> Tested-by: Tony Luck <tony.luck@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Mike Travis <travis@sgi.com> Cc: ink@jurassic.park.msu.ru Cc: rmk@arm.linux.org.uk Cc: starvik@axis.com Cc: tony.luck@intel.com Cc: takata@linux-m32r.org Cc: ralf@linux-mips.org Cc: grundler@parisc-linux.org Cc: paulus@samba.org Cc: schwidefsky@de.ibm.com Cc: lethal@linux-sh.org Cc: wli@holomorphy.com Cc: davem@davemloft.net Cc: jdike@addtoit.com Cc: mingo@redhat.com
| * | | | | | | kbuild: Remove gcc 4.1.0 quirk from init/main.cIngo Molnar2009-01-021-9/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: cleanup We now have a cleaner check for gcc 4.1.0/4.1.1 trouble in include/linux/compiler-gcc4.h, so remove the 4.1.0 quirk from init/main.c. Reported-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | | | | Merge branch 'irq-fixes-for-linus-4' of ↵Linus Torvalds2008-12-311-9/+0
| |\ \ \ \ \ \ \ | | |_|_|_|_|_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'irq-fixes-for-linus-4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sparseirq: move __weak symbols into separate compilation unit sparseirq: work around __weak alias bug sparseirq: fix hang with !SPARSE_IRQ sparseirq: set lock_class for legacy irq when sparse_irq is selected sparseirq: work around compiler optimizing away __weak functions sparseirq: fix desc->lock init sparseirq: do not printk when migrating IRQ descriptors sparseirq: remove duplicated arch_early_irq_init() irq: simplify for_each_irq_desc() usage proc: remove ifdef CONFIG_SPARSE_IRQ from stat.c irq: for_each_irq_desc() move to irqnr.h hrtimer: remove #include <linux/irq.h>
| | * | | | | | sparseirq: move __weak symbols into separate compilation unitYinghai Lu2008-12-291-10/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | GCC has a bug with __weak alias functions: if the functions are in the same compilation unit as their call site, GCC can decide to inline them - and thus rob the linker of the opportunity to override the weak alias with the real thing. So move all the IRQ handling related __weak symbols to kernel/irq/chip.c. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | sparseirq: work around compiler optimizing away __weak functionsYinghai Lu2008-12-271-3/+4
| | | |_|/ / / | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: fix panic on null pointer with sparseirq Some GCC versions seem to inline the weak global function, when that function is empty. Work it around, by making the functions return a (dummy) integer. Signed-off-by: Yinghai <yinghai@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | | | | Merge branch 'linus' into stackprotectorIngo Molnar2008-12-315-38/+233
|\ \ \ \ \ \ \ | |/ / / / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: arch/x86/include/asm/pda.h kernel/fork.c
| * | | | | | Merge branch 'irq-core-for-linus' of ↵Linus Torvalds2008-12-301-0/+11
| |\ \ \ \ \ \ | | |/ / / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86, sparseirq: clean up Kconfig entry x86: turn CONFIG_SPARSE_IRQ off by default sparseirq: fix numa_migrate_irq_desc dependency and comments sparseirq: add kernel-doc notation for new member in irq_desc, -v2 locking, irq: enclose irq_desc_lock_class in CONFIG_LOCKDEP sparseirq, xen: make sure irq_desc is allocated for interrupts sparseirq: fix !SMP building, #2 x86, sparseirq: move irq_desc according to smp_affinity, v7 proc: enclose desc variable of show_stat() in CONFIG_SPARSE_IRQ sparse irqs: add irqnr.h to the user headers list sparse irqs: handle !GENIRQ platforms sparseirq: fix !SMP && !PCI_MSI && !HT_IRQ build sparseirq: fix Alpha build failure sparseirq: fix typo in !CONFIG_IO_APIC case x86, MSI: pass irq_cfg and irq_desc x86: MSI start irq numbering from nr_irqs_gsi x86: use NR_IRQS_LEGACY sparse irq_desc[] array: core kernel and x86 changes genirq: record IRQ_LEVEL in irq_desc[] irq.h: remove padding from irq_desc on 64bits
| | * | | | | sparse irq_desc[] array: core kernel and x86 changesYinghai Lu2008-12-081-0/+11
| | |/ / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: new feature Problem on distro kernels: irq_desc[NR_IRQS] takes megabytes of RAM with NR_CPUS set to large values. The goal is to be able to scale up to much larger NR_IRQS value without impacting the (important) common case. To solve this, we generalize irq_desc[NR_IRQS] to an (optional) array of irq_desc pointers. When CONFIG_SPARSE_IRQ=y is used, we use kzalloc_node to get irq_desc, this also makes the IRQ descriptors NUMA-local (to the site that calls request_irq()). This gets rid of the irq_cfg[] static array on x86 as well: irq_cfg now uses desc->chip_data for x86 to store irq_cfg. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | Merge branch 'core-for-linus' of ↵Linus Torvalds2008-12-301-3/+83
| |\ \ \ \ \ | | |_|_|_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (63 commits) stacktrace: provide save_stack_trace_tsk() weak alias rcu: provide RCU options on non-preempt architectures too printk: fix discarding message when recursion_bug futex: clean up futex_(un)lock_pi fault handling "Tree RCU": scalable classic RCU implementation futex: rename field in futex_q to clarify single waiter semantics x86/swiotlb: add default swiotlb_arch_range_needs_mapping x86/swiotlb: add default phys<->bus conversion x86: unify pci iommu setup and allow swiotlb to compile for 32 bit x86: add swiotlb allocation functions swiotlb: consolidate swiotlb info message printing swiotlb: support bouncing of HighMem pages swiotlb: factor out copy to/from device swiotlb: add arch hook to force mapping swiotlb: allow architectures to override phys<->bus<->phys conversions swiotlb: add comment where we handle the overflow of a dma mask on 32 bit rcu: fix rcutorture behavior during reboot resources: skip sanity check of busy resources swiotlb: move some definitions to header swiotlb: allow architectures to override swiotlb pool allocation ... Fix up trivial conflicts in arch/x86/kernel/Makefile arch/x86/mm/init_32.c include/linux/hardirq.h as per Ingo's suggestions.
| | * | | | rcu: provide RCU options on non-preempt architectures tooIngo Molnar2008-12-251-0/+74
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: build fix Some old architectures still do not use kernel/Kconfig.preempt, so the moving of the RCU options there broke their build: In file included from /home/mingo/tip/include/linux/sem.h:81, from /home/mingo/tip/include/linux/sched.h:69, from /home/mingo/tip/arch/alpha/kernel/asm-offsets.c:9: /home/mingo/tip/include/linux/rcupdate.h:62:2: error: #error "Unknown RCU implementation specified to kernel configuration" Move these options back to init/Kconfig, which every architecture includes. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | "Tree RCU": scalable classic RCU implementationPaul E. McKenney2008-12-181-6/+12
| | |/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes a long-standing performance bug in classic RCU that results in massive internal-to-RCU lock contention on systems with more than a few hundred CPUs. Although this patch creates a separate flavor of RCU for ease of review and patch maintenance, it is intended to replace classic RCU. This patch still handles stress better than does mainline, so I am still calling it ready for inclusion. This patch is against the -tip tree. Nevertheless, experience on an actual 1000+ CPU machine would still be most welcome. Most of the changes noted below were found while creating an rcutiny (which should permit ejecting the current rcuclassic) and while doing detailed line-by-line documentation. Updates from v9 (http://lkml.org/lkml/2008/12/2/334): o Fixes from remainder of line-by-line code walkthrough, including comment spelling, initialization, undesirable narrowing due to type conversion, removing redundant memory barriers, removing redundant local-variable initialization, and removing redundant local variables. I do not believe that any of these fixes address the CPU-hotplug issues that Andi Kleen was seeing, but please do give it a whirl in case the machine is smarter than I am. A writeup from the walkthrough may be found at the following URL, in case you are suffering from terminal insomnia or masochism: http://www.kernel.org/pub/linux/kernel/people/paulmck/tmp/rcutree-walkthrough.2008.12.16a.pdf o Made rcutree tracing use seq_file, as suggested some time ago by Lai Jiangshan. o Added a .csv variant of the rcudata debugfs trace file, to allow people having thousands of CPUs to drop the data into a spreadsheet. Tested with oocalc and gnumeric. Updated documentation to suit. Updates from v8 (http://lkml.org/lkml/2008/11/15/139): o Fix a theoretical race between grace-period initialization and force_quiescent_state() that could occur if more than three jiffies were required to carry out the grace-period initialization. Which it might, if you had enough CPUs. o Apply Ingo's printk-standardization patch. o Substitute local variables for repeated accesses to global variables. o Fix comment misspellings and redundant (but harmless) increments of ->n_rcu_pending (this latter after having explicitly added it). o Apply checkpatch fixes. Updates from v7 (http://lkml.org/lkml/2008/10/10/291): o Fixed a number of problems noted by Gautham Shenoy, including the cpu-stall-detection bug that he was having difficulty convincing me was real. ;-) o Changed cpu-stall detection to wait for ten seconds rather than three in order to reduce false positive, as suggested by Ingo Molnar. o Produced a design document (http://lwn.net/Articles/305782/). The act of writing this document uncovered a number of both theoretical and "here and now" bugs as noted below. o Fix dynticks_nesting accounting confusion, simplify WARN_ON() condition, fix kerneldoc comments, and add memory barriers in dynticks interface functions. o Add more data to tracing. o Remove unused "rcu_barrier" field from rcu_data structure. o Count calls to rcu_pending() from scheduling-clock interrupt to use as a surrogate timebase should jiffies stop counting. o Fix a theoretical race between force_quiescent_state() and grace-period initialization. Yes, initialization does have to go on for some jiffies for this race to occur, but given enough CPUs... Updates from v6 (http://lkml.org/lkml/2008/9/23/448): o Fix a number of checkpatch.pl complaints. o Apply review comments from Ingo Molnar and Lai Jiangshan on the stall-detection code. o Fix several bugs in !CONFIG_SMP builds. o Fix a misspelled config-parameter name so that RCU now announces at boot time if stall detection is configured. o Run tests on numerous combinations of configurations parameters, which after the fixes above, now build and run correctly. Updates from v5 (http://lkml.org/lkml/2008/9/15/92, bad subject line): o Fix a compiler error in the !CONFIG_FANOUT_EXACT case (blew a changeset some time ago, and finally got around to retesting this option). o Fix some tracing bugs in rcupreempt that caused incorrect totals to be printed. o I now test with a more brutal random-selection online/offline script (attached). Probably more brutal than it needs to be on the people reading it as well, but so it goes. o A number of optimizations and usability improvements: o Make rcu_pending() ignore the grace-period timeout when there is no grace period in progress. o Make force_quiescent_state() avoid going for a global lock in the case where there is no grace period in progress. o Rearrange struct fields to improve struct layout. o Make call_rcu() initiate a grace period if RCU was idle, rather than waiting for the next scheduling clock interrupt. o Invoke rcu_irq_enter() and rcu_irq_exit() only when idle, as suggested by Andi Kleen. I still don't completely trust this change, and might back it out. o Make CONFIG_RCU_TRACE be the single config variable manipulated for all forms of RCU, instead of the prior confusion. o Document tracing files and formats for both rcupreempt and rcutree. Updates from v4 for those missing v5 given its bad subject line: o Separated dynticks interface so that NMIs and irqs call separate functions, greatly simplifying it. In particular, this code no longer requires a proof of correctness. ;-) o Separated dynticks state out into its own per-CPU structure, avoiding the duplicated accounting. o The case where a dynticks-idle CPU runs an irq handler that invokes call_rcu() is now correctly handled, forcing that CPU out of dynticks-idle mode. o Review comments have been applied (thank you all!!!). For but one example, fixed the dynticks-ordering issue that Manfred pointed out, saving me much debugging. ;-) o Adjusted rcuclassic and rcupreempt to handle dynticks changes. Attached is an updated patch to Classic RCU that applies a hierarchy, greatly reducing the contention on the top-level lock for large machines. This passes 10-hour concurrent rcutorture and online-offline testing on 128-CPU ppc64 without dynticks enabled, and exposes some timekeeping bugs in presence of dynticks (exciting working on a system where "sleep 1" hangs until interrupted...), which were fixed in the 2.6.27 kernel. It is getting more reliable than mainline by some measures, so the next version will be against -tip for inclusion. See also Manfred Spraul's recent patches (or his earlier work from 2004 at http://marc.info/?l=linux-kernel&m=108546384711797&w=2). We will converge onto a common patch in the fullness of time, but are currently exploring different regions of the design space. That said, I have already gratefully stolen quite a few of Manfred's ideas. This patch provides CONFIG_RCU_FANOUT, which controls the bushiness of the RCU hierarchy. Defaults to 32 on 32-bit machines and 64 on 64-bit machines. If CONFIG_NR_CPUS is less than CONFIG_RCU_FANOUT, there is no hierarchy. By default, the RCU initialization code will adjust CONFIG_RCU_FANOUT to balance the hierarchy, so strongly NUMA architectures may choose to set CONFIG_RCU_FANOUT_EXACT to disable this balancing, allowing the hierarchy to be exactly aligned to the underlying hardware. Up to two levels of hierarchy are permitted (in addition to the root node), allowing up to 16,384 CPUs on 32-bit systems and up to 262,144 CPUs on 64-bit systems. I just know that I am going to regret saying this, but this seems more than sufficient for the foreseeable future. (Some architectures might wish to set CONFIG_RCU_FANOUT=4, which would limit such architectures to 64 CPUs. If this becomes a real problem, additional levels can be added, but I doubt that it will make a significant difference on real hardware.) In the common case, a given CPU will manipulate its private rcu_data structure and the rcu_node structure that it shares with its immediate neighbors. This can reduce both lock and memory contention by multiple orders of magnitude, which should eliminate the need for the strange manipulations that are reported to be required when running Linux on very large systems. Some shortcomings: o More bugs will probably surface as a result of an ongoing line-by-line code inspection. Patches will be provided as required. o There are probably hangs, rcutorture failures, &c. Seems quite stable on a 128-CPU machine, but that is kind of small compared to 4096 CPUs. However, seems to do better than mainline. Patches will be provided as required. o The memory footprint of this version is several KB larger than rcuclassic. A separate UP-only rcutiny patch will be provided, which will reduce the memory footprint significantly, even compared to the old rcuclassic. One such patch passes light testing, and has a memory footprint smaller even than rcuclassic. Initial reaction from various embedded guys was "it is not worth it", so am putting it aside. Credits: o Manfred Spraul for ideas, review comments, and bugs spotted, as well as some good friendly competition. ;-) o Josh Triplett, Ingo Molnar, Peter Zijlstra, Mathieu Desnoyers, Lai Jiangshan, Andi Kleen, Andy Whitcroft, and Andrew Morton for reviews and comments. o Thomas Gleixner for much-needed help with some timer issues (see patches below). o Jon M. Tollefson, Tim Pepper, Andrew Theurer, Jose R. Santos, Andy Whitcroft, Darrick Wong, Nishanth Aravamudan, Anton Blanchard, Dave Kleikamp, and Nathan Lynch for keeping machines alive despite my heavy abuse^Wtesting. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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