kernel.git/arch/powerpc/kernel/smp.c, branch linux-3.18.y

powerpc: Only set numa node information for present cpus at boottime

2014-09-25T13:14:53Z

As Nish suggested, it makes more sense to init the numa node informatiion for present cpus at boottime, which could also avoid WARN_ON(1) in numa_setup_cpu(). With this change, we also need to change the smp_prepare_cpus() to set up numa information only on present cpus. For those possible, but not present cpus, their numa information will be set up after they are started, as the original code did before commit 2fabf084b6ad. Cc: Nishanth Aravamudan Cc: Nathan Fontenot Signed-off-by: Li Zhong Acked-by: Nishanth Aravamudan Tested-by: Cyril Bur Signed-off-by: Michael Ellerman

powerpc: Ensure global functions include their prototype

2014-09-25T13:14:42Z

Fix a number of places where global functions were not including their prototype. This ensures the prototype and the function match. Signed-off-by: Anton Blanchard Signed-off-by: Michael Ellerman

powerpc: reorder per-cpu NUMA information's initialization

2014-08-13T05:14:05Z

There is an issue currently where NUMA information is used on powerpc (and possibly ia64) before it has been read from the device-tree, which leads to large slab consumption with CONFIG_SLUB and memoryless nodes. NUMA powerpc non-boot CPU's cpu_to_node/cpu_to_mem is only accurate after start_secondary(), similar to ia64, which is invoked via smp_init(). Commit 6ee0578b4daae ("workqueue: mark init_workqueues() as early_initcall()") made init_workqueues() be invoked via do_pre_smp_initcalls(), which is obviously before the secondary processors are online. Additionally, the following commits changed init_workqueues() to use cpu_to_node to determine the node to use for kthread_create_on_node: bce903809ab3f ("workqueue: add wq_numa_tbl_len and wq_numa_possible_cpumask[]") f3f90ad469342 ("workqueue: determine NUMA node of workers accourding to the allowed cpumask") Therefore, when init_workqueues() runs, it sees all CPUs as being on Node 0. On LPARs or KVM guests where Node 0 is memoryless, this leads to a high number of slab deactivations (http://www.spinics.net/lists/linux-mm/msg67489.html). Fix this by initializing the powerpc-specific CPU<->node/local memory node mapping as early as possible, which on powerpc is do_init_bootmem(). Currently that function initializes the mapping for the boot CPU, but we extend it to setup the mapping for all possible CPUs. Then, in smp_prepare_cpus(), we can correspondingly set the per-cpu values for all possible CPUs. That ensures that before the early_initcalls run (and really as early as possible), the per-cpu NUMA mapping is accurate. While testing memoryless nodes on PowerKVM guests with a fix to the workqueue logic to use cpu_to_mem() instead of cpu_to_node(), with a guest topology of: available: 2 nodes (0-1) node 0 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 node 0 size: 0 MB node 0 free: 0 MB node 1 cpus: 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 node 1 size: 16336 MB node 1 free: 15329 MB node distances: node 0 1 0: 10 40 1: 40 10 the slab consumption decreases from Slab: 932416 kB SUnreclaim: 902336 kB to Slab: 395264 kB SUnreclaim: 359424 kB And we a corresponding increase in the slab efficiency from slab mem objs slabs used active active ------------------------------------------------------------ kmalloc-16384 337 MB 11.28% 100.00% task_struct 288 MB 9.93% 100.00% to slab mem objs slabs used active active ------------------------------------------------------------ kmalloc-16384 37 MB 100.00% 100.00% task_struct 31 MB 100.00% 100.00% Powerpc didn't support memoryless nodes until recently (64bb80d87f01 "powerpc/numa: Enable CONFIG_HAVE_MEMORYLESS_NODES" and 8c272261194d "powerpc/numa: Enable USE_PERCPU_NUMA_NODE_ID"). Those commits also helped improve memory consumption with these kind of environments. Signed-off-by: Nishanth Aravamudan Signed-off-by: Benjamin Herrenschmidt

sched: Fix compiler warnings

2014-07-02T06:33:48Z

Commit 143e1e28cb (sched: Rework sched_domain topology definition) introduced a number of functions with a return value of 'const int'. gcc doesn't know what to do with that and, if the kernel is compiled with W=1, complains with the following warnings whenever sched.h is included. include/linux/sched.h:875:25: warning: type qualifiers ignored on function return type include/linux/sched.h:882:25: warning: type qualifiers ignored on function return type include/linux/sched.h:889:25: warning: type qualifiers ignored on function return type include/linux/sched.h:1002:21: warning: type qualifiers ignored on function return type Commits fb2aa855 (sched, ARM: Create a dedicated scheduler topology table) and 607b45e9a (sched, powerpc: Create a dedicated topology table) introduce the same warning in the arm and powerpc code. Drop 'const' from the function declarations to fix the problem. The fix for all three patches has to be applied together to avoid compilation failures for the affected architectures. Acked-by: Vincent Guittot Acked-by: Benjamin Herrenschmidt Signed-off-by: Guenter Roeck Cc: Russell King Cc: Paul Mackerras Cc: Dietmar Eggemann Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1403658329-13196-1-git-send-email-linux@roeck-us.net Signed-off-by: Ingo Molnar

Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2014-06-13T02:42:15Z

Pull more scheduler updates from Ingo Molnar: "Second round of scheduler changes: - try-to-wakeup and IPI reduction speedups, from Andy Lutomirski - continued power scheduling cleanups and refactorings, from Nicolas Pitre - misc fixes and enhancements" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/deadline: Delete extraneous extern for to_ratio() sched/idle: Optimize try-to-wake-up IPI sched/idle: Simplify wake_up_idle_cpu() sched/idle: Clear polling before descheduling the idle thread sched, trace: Add a tracepoint for IPI-less remote wakeups cpuidle: Set polling in poll_idle sched: Remove redundant assignment to "rt_rq" in update_curr_rt(...) sched: Rename capacity related flags sched: Final power vs. capacity cleanups sched: Remove remaining dubious usage of "power" sched: Let 'struct sched_group_power' care about CPU capacity sched/fair: Disambiguate existing/remaining "capacity" usage sched/fair: Change "has_capacity" to "has_free_capacity" sched/fair: Remove "power" from 'struct numa_stats' sched: Fix signedness bug in yield_to() sched/fair: Use time_after() in record_wakee() sched/balancing: Reduce the rate of needless idle load balancing sched/fair: Fix unlocked reads of some cfs_b->quota/period

Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc

2014-06-11T01:54:22Z

Pull powerpc updates from Ben Herrenschmidt: "Here is the bulk of the powerpc changes for this merge window. It got a bit delayed in part because I wasn't paying attention, and in part because I discovered I had a core PCI change without a PCI maintainer ack in it. Bjorn eventually agreed it was ok to merge it though we'll probably improve it later and I didn't want to rebase to add his ack. There is going to be a bit more next week, essentially fixes that I still want to sort through and test. The biggest item this time is the support to build the ppc64 LE kernel with our new v2 ABI. We previously supported v2 userspace but the kernel itself was a tougher nut to crack. This is now sorted mostly thanks to Anton and Rusty. We also have a fairly big series from Cedric that add support for 64-bit LE zImage boot wrapper. This was made harder by the fact that traditionally our zImage wrapper was always 32-bit, but our new LE toolchains don't really support 32-bit anymore (it's somewhat there but not really "supported") so we didn't want to rely on it. This meant more churn that just endian fixes. This brings some more LE bits as well, such as the ability to run in LE mode without a hypervisor (ie. under OPAL firmware) by doing the right OPAL call to reinitialize the CPU to take HV interrupts in the right mode and the usual pile of endian fixes. There's another series from Gavin adding EEH improvements (one day we *will* have a release with less than 20 EEH patches, I promise!). Another highlight is the support for the "Split core" functionality on P8 by Michael. This allows a P8 core to be split into "sub cores" of 4 threads which allows the subcores to run different guests under KVM (the HW still doesn't support a partition per thread). And then the usual misc bits and fixes ..." [ Further delayed by gmail deciding that BenH is a dirty spammer. Google knows. ] * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (155 commits) powerpc/powernv: Add missing include to LPC code selftests/powerpc: Test the THP bug we fixed in the previous commit powerpc/mm: Check paca psize is up to date for huge mappings powerpc/powernv: Pass buffer size to OPAL validate flash call powerpc/pseries: hcall functions are exported to modules, need _GLOBAL_TOC() powerpc: Exported functions __clear_user and copy_page use r2 so need _GLOBAL_TOC() powerpc/powernv: Set memory_block_size_bytes to 256MB powerpc: Allow ppc_md platform hook to override memory_block_size_bytes powerpc/powernv: Fix endian issues in memory error handling code powerpc/eeh: Skip eeh sysfs when eeh is disabled powerpc: 64bit sendfile is capped at 2GB powerpc/powernv: Provide debugfs access to the LPC bus via OPAL powerpc/serial: Use saner flags when creating legacy ports powerpc: Add cpu family documentation powerpc/xmon: Fix up xmon format strings powerpc/powernv: Add calls to support little endian host powerpc: Document sysfs DSCR interface powerpc: Fix regression of per-CPU DSCR setting powerpc: Split __SYSFS_SPRSETUP macro arch: powerpc/fadump: Cleaning up inconsistent NULL checks ...

sched: Rename capacity related flags

2014-06-05T09:52:32Z

It is better not to think about compute capacity as being equivalent to "CPU power". The upcoming "power aware" scheduler work may create confusion with the notion of energy consumption if "power" is used too liberally. Let's rename the following feature flags since they do relate to capacity: SD_SHARE_CPUPOWER -> SD_SHARE_CPUCAPACITY ARCH_POWER -> ARCH_CAPACITY NONTASK_POWER -> NONTASK_CAPACITY Signed-off-by: Nicolas Pitre Signed-off-by: Peter Zijlstra Cc: Vincent Guittot Cc: Daniel Lezcano Cc: Morten Rasmussen Cc: "Rafael J. Wysocki" Cc: linaro-kernel@lists.linaro.org Cc: Andy Fleming Cc: Anton Blanchard Cc: Benjamin Herrenschmidt Cc: Grant Likely Cc: Linus Torvalds Cc: Michael Ellerman Cc: Paul Gortmaker Cc: Paul Mackerras Cc: Preeti U Murthy Cc: Rob Herring Cc: Srivatsa S. Bhat Cc: Toshi Kani Cc: Vasant Hegde Cc: Vincent Guittot Cc: devicetree@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/n/tip-e93lpnxb87owfievqatey6b5@git.kernel.org Signed-off-by: Ingo Molnar

powerpc: Check cpu_thread_in_subcore() in __cpu_up()

2014-05-28T03:35:36Z

To support split core we need to change the check in __cpu_up() that determines if a cpu is allowed to come online. Currently we refuse to online cpus which are not the primary thread within their core. On POWER8 with split core support this check needs to instead refuse to online cpus which are not the primary thread within their *sub* core. On POWER7 and other systems that do not support split core, threads_per_subcore == threads_per_core and so the check is equivalent. Signed-off-by: Michael Ellerman Signed-off-by: Michael Neuling Signed-off-by: Benjamin Herrenschmidt

powerpc/kvm/book3s_hv: Rework the secondary inhibit code

2014-05-28T03:35:34Z

As part of the support for split core on POWER8, we want to be able to block splitting of the core while KVM VMs are active. The logic to do that would be exactly the same as the code we currently have for inhibiting onlining of secondaries. Instead of adding an identical mechanism to block split core, rework the secondary inhibit code to be a "HV KVM is active" check. We can then use that in both the cpu hotplug code and the upcoming split core code. Signed-off-by: Michael Ellerman Signed-off-by: Michael Neuling Acked-by: Alexander Graf Acked-by: Paul Mackerras Signed-off-by: Benjamin Herrenschmidt

powerpc/numa: Enable CONFIG_HAVE_MEMORYLESS_NODES

2014-05-28T03:35:34Z

Based off fd1197f1 for ia64, enable CONFIG_HAVE_MEMORYLESS_NODES if NUMA. Initialize the local memory node in start_secondary. With this commit and the preceding to enable CONFIG_USER_PERCPU_NUMA_NODE_ID, which is a prerequisite, in a PowerKVM guest with the following topology: numactl --hardware available: 3 nodes (0-2) node 0 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 node 0 size: 1998 MB node 0 free: 521 MB node 1 cpus: 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 node 1 size: 0 MB node 1 free: 0 MB node 2 cpus: node 2 size: 2039 MB node 2 free: 1739 MB node distances: node 0 1 2 0: 10 40 40 1: 40 10 40 2: 40 40 10 the unreclaimable slab is reduced by close to 130M: Before: Slab: 418176 kB SReclaimable: 26624 kB SUnreclaim: 391552 kB After: Slab: 298944 kB SReclaimable: 31744 kB SUnreclaim: 267200 kB Signed-off-by: Nishanth Aravamudan Signed-off-by: Benjamin Herrenschmidt