linux/kernel/cpu.c, branch v2.6.30

cpumask: use set_cpu_active in init/main.c

2009-03-30T11:35:12Z

cpu_active_map is deprecated in favor of cpu_active_mask, which is const for safety: we use accessors now (set_cpu_active) is we really want to make a change. Signed-off-by: Rusty Russell

stop_machine/cpu hotplug: fix disable_nonboot_cpus

2009-01-07T19:36:14Z

disable_nonboot_cpus calls _cpu_down. But _cpu_down requires that the caller already created the stop_machine workqueue (like cpu_down does). Otherwise a call to stop_machine will lead to accesses to random memory regions. When introducing this new interface (9ea09af3bd3090e8349ca2899ca2011bd94cda85 "stop_machine: introduce stop_machine_create/destroy") I missed the second call site of _cpu_down. So add the missing stop_machine_create/destroy calls to disable_nonboot_cpus as well. Fixes suspend-to-ram/disk and also this bug: [ 286.547348] BUG: unable to handle kernel paging request at 6b6b6b6b [ 286.548940] IP: [] __stop_machine+0x88/0xe3 [ 286.550598] Oops: 0002 [#1] SMP [ 286.560580] Pid: 3273, comm: halt Not tainted (2.6.28-06127-g238c6d5 [ 286.560580] EIP: is at __stop_machine+0x88/0xe3 [ 286.560580] Process halt (pid: 3273, ti=f1a28000 task=f4530f30 [ 286.560580] Call Trace: [ 286.560580] [] ? _cpu_down+0x10f/0x234 [ 286.560580] [] ? disable_nonboot_cpus+0x58/0xdc [ 286.560580] [] ? kernel_poweroff+0x22/0x39 [ 286.560580] [] ? sys_reboot+0xde/0x14c [ 286.560580] [] ? complete_signal+0x179/0x191 [ 286.560580] [] ? send_signal+0x1cc/0x1e1 [ 286.560580] [] ? _spin_unlock_irqrestore+0x2d/0x3c [ 286.560580] [] ? group_send_signal_info+0x58/0x61 [ 286.560580] [] ? kill_pid_info+0x30/0x3a [ 286.560580] [] ? sys_kill+0x75/0x13a [ 286.560580] [] ? mntput_no_expire+ox1f/0x101 [ 286.560580] [] ? dput+0x1e/0x105 [ 286.560580] [] ? __fput+0x150/0x158 [ 286.560580] [] ? audit_syscall_entry+0x137/0x159 [ 286.560580] [] ? sysenter_do_call+0x12/0x34 Reported-and-tested-by: "Justin P. Mattock" Reviewed-by: Pekka Enberg Signed-off-by: Heiko Carstens Tested-by: Ingo Molnar Signed-off-by: Linus Torvalds

stop_machine: introduce stop_machine_create/destroy.

2009-01-04T22:10:14Z

Introduce stop_machine_create/destroy. With this interface subsystems that need a non-failing stop_machine environment can create the stop_machine machine threads before actually calling stop_machine. When the threads aren't needed anymore they can be killed with stop_machine_destroy again. When stop_machine gets called and the threads aren't present they will be created and destroyed automatically. This restores the old behaviour of stop_machine. This patch also converts cpu hotplug to the new interface since it is special: cpu_down calls __stop_machine instead of stop_machine. However the kstop threads will only be created when stop_machine gets called. Changing the code so that the threads would be created automatically on __stop_machine is currently not possible: when __stop_machine gets called we hold cpu_add_remove_lock, which is the same lock that create_rt_workqueue would take. So the workqueue needs to be created before the cpu hotplug code locks cpu_add_remove_lock. Signed-off-by: Heiko Carstens Signed-off-by: Rusty Russell

cpumask: convert kernel/cpu.c

2008-12-31T23:42:28Z

Impact: Reduce kernel stack and memory usage, use new cpumask API. Use cpumask_var_t for take_cpu_down() stack var, and frozen_cpus. Note that notify_cpu_starting() can be called before core_initcall allocates frozen_cpus, but the NULL check is optimized out by gcc for the CONFIG_CPUMASK_OFFSTACK=n case. Signed-off-by: Rusty Russell

cpumask: make set_cpu_/init_cpu_ out-of-line

2008-12-29T22:35:16Z

They're only for use in boot/cpu hotplug code anyway, and this avoids the use of deprecated cpu_*_map. Stephen Rothwell points out that gcc 4.2.4 (on powerpc at least) didn't like the cast away of const anyway: include/linux/cpumask.h: In function 'set_cpu_possible': include/linux/cpumask.h:1052: warning: passing argument 2 of 'cpumask_set_cpu' discards qualifiers from pointer target type So this kills two birds with one stone. Signed-off-by: Rusty Russell

cpumask: switch over to cpu_online/possible/active/present_mask: core

2008-12-29T22:35:14Z

Impact: cleanup This implements the obsolescent cpu_online_map in terms of cpu_online_mask, rather than the other way around. Same for the other maps. The documentation comments are also updated to refer to _mask rather than _map. Signed-off-by: Rusty Russell Signed-off-by: Mike Travis

cpumask: centralize cpu_online_map and cpu_possible_map

2008-12-13T10:49:41Z

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 Reviewed-by: Grant Grundler Tested-by: Tony Luck Acked-by: Ingo Molnar Cc: Mike Travis 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

cpuinit fixes in kernel/*

2008-11-30T18:03:37Z

Signed-off-by: Al Viro Signed-off-by: Linus Torvalds

cpumask: introduce new API, without changing anything

2008-11-06T08:05:33Z

Impact: introduce new APIs We want to deprecate cpumasks on the stack, as we are headed for gynormous numbers of CPUs. Eventually, we want to head towards an undefined 'struct cpumask' so they can never be declared on stack. 1) New cpumask functions which take pointers instead of copies. (cpus_* -> cpumask_*) 2) Several new helpers to reduce requirements for temporary cpumasks (cpumask_first_and, cpumask_next_and, cpumask_any_and) 3) Helpers for declaring cpumasks on or offstack for large NR_CPUS (cpumask_var_t, alloc_cpumask_var and free_cpumask_var) 4) 'struct cpumask' for explicitness and to mark new-style code. 5) Make iterator functions stop at nr_cpu_ids (a runtime constant), not NR_CPUS for time efficiency and for smaller dynamic allocations in future. 6) cpumask_copy() so we can allocate less than a full cpumask eventually (for alloc_cpumask_var), and so we can eliminate the 'struct cpumask' definition eventually. 7) work_on_cpu() helper for doing task on a CPU, rather than saving old cpumask for current thread and manipulating it. 8) smp_call_function_many() which is smp_call_function_mask() except taking a cpumask pointer. Note that this patch simply introduces the new functions and leaves the obsolescent ones in place. This is to simplify the transition patches. Signed-off-by: Rusty Russell Signed-off-by: Ingo Molnar

Merge branches 'sched/devel', 'sched/cpu-hotplug', 'sched/cpusets' and 'sched/urgent' into sched/core

2008-10-08T09:31:02Z