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2018-02-23Merge branches 'fixes.2018.02.23a', 'srcu.2018.02.20a' and ↵Paul E. McKenney
'torture.2018.02.20a' into HEAD fixes.2018.02.23a: Miscellaneous fixes srcu.2018.02.20a: SRCU updates torture.2018.02.20a: Torture-test updates
2018-02-23rcu: Create RCU-specific workqueues with rescuersPaul E. McKenney
RCU's expedited grace periods can participate in out-of-memory deadlocks due to all available system_wq kthreads being blocked and there not being memory available to create more. This commit prevents such deadlocks by allocating an RCU-specific workqueue_struct at early boot time, and providing it with a rescuer to ensure forward progress. This uses the shiny new init_rescuer() function provided by Tejun (but indirectly). This commit also causes SRCU to use this new RCU-specific workqueue_struct. Note that SRCU's use of workqueues never blocks them waiting for readers, so this should be safe from a forward-progress viewpoint. Note that this moves SRCU from system_power_efficient_wq to a normal workqueue. In the unlikely event that this results in measurable degradation, a separate power-efficient workqueue will be creates for SRCU. Reported-by: Prateek Sood <prsood@codeaurora.org> Reported-by: Tejun Heo <tj@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Tejun Heo <tj@kernel.org>
2018-02-20torture: Provide more sensible nreader/nwriter defaults for rcuperfPaul E. McKenney
The default values for nreader and nwriter are apparently not all that user-friendly, resulting in people doing scalability tests that ran all runs at large scale. This commit therefore makes both the nreaders and nwriters module default to the number of CPUs, and adds a comment to rcuperf.c stating that the number of CPUs should be specified using the nr_cpus kernel boot parameter. This commit also eliminates the redundant rcuperf scripting specification of default values for these parameters. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-20torture: Grace periods do not piggyback off of themselvesPaul E. McKenney
The rcuperf trace-event processing counted every "done" trace event as a piggyback, which is incorrect because the task that started the grace period didn't piggyback at all. This commit fixes this problem by recording the task that started a given grace period and ignoring that task's "done" record for that grace period. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-20torture: Adjust rcuperf trace processing to allow for workqueuesPaul E. McKenney
The rcuperf event-trace processing assumes that expedited grace periods start and end on the same task, an assumption that was violated by moving expedited grace-period processing to workqueues. This commit removes this now-fallacious assumption from rcuperf's event-trace processing. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-20torture: Default jitter off when running rcuperfPaul E. McKenney
The purpose of jitter is to expose concurrency bugs due to invalid assumptions about forward progress. There is usually little point in jitter when measuring performance. This commit therefore defaults jitter off when running rcuperf. You can override this by specifying the kvm.sh "--jitter" argument -after- the "--torture rcuperf" argument. No idea why you would want this, but if you do, that is how you do it. One example of a conccurrency bug that this jitter might expose is one in which the developer assumed that a given short region of code would be guaranteed to execute within some short time limit. Such assumptions are invalid in virtualized environments because the hupervisor can preempt the guest OS at any point, even when the guest OS thinks that it has disabled interrupts. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-20torture: Specify qemu memory size with --memory argumentPaul E. McKenney
The 512 megabyte memory size has served quite well, but more memory is required when using large trace buffers on large systems. This commit therefore adds a --memory argument to the kvm.sh script, which allows the memory size to be specified on the command line, for example, "--memory 768", --memory 800M", or "--memory 2G". Reported-by: Sebastian Siewior <bigeasy@linutronix.de> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-20rcutorture: Add basic ARM64 support to run scriptsLihao Liang
This commit adds support of the qemu command qemu-system-aarch64 to rcutorture. Signed-off-by: Lihao Liang <lianglihao@huawei.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-20rcutorture: Update kvm.sh header commentPaul E. McKenney
The kvm.sh header comment is a bit of a relic, so this commit brings it up to date. Reported-by: Lihao Liang <lianglihao@huawei.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-20rcutorture: Record which grace-period primitives are testedPaul E. McKenney
The rcu_torture_writer() function adapts to requested testing from module parameters as well as the function pointers in the structure referenced by cur_ops. However, as long as the module parameters do not conflict with the function pointers, this adaptation is silent. This silence can result in confusion as to exactly what was tested, which could in turn result in untested RCU code making its way into mainline. This commit therefore makes rcu_torture_writer() announce exactly which portions of RCU's API it ends up testing. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-20rcutorture: Re-enable testing of dynamic expeditingPaul E. McKenney
During boot, normal grace periods are processed as expedited. When rcutorture is built into the kernel, it starts during boot and thus detects that normal grace periods are unconditionally expedited. Therefore, rcutorture concludes that there is no point in trying to dynamically enable expediting, do it disables this aspect of testing, which is a bit of an overreaction to the temporary boot-time expediting. This commit therefore rechecks forced expediting throughout the test, enabling dynamic expediting if normal grace periods are processed normally at any point. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-20rcutorture: Avoid fake-writer use of undefined primitivesPaul E. McKenney
Currently the rcu_torture_fakewriter() function invokes cur_ops->sync() and cur_ops->exp_sync() without first checking to see if they are in fact non-NULL. This results in kernel NULL pointer dereferences when testing RCU implementations that choose not to provide the full set of primitives. Given that it is perfectly reasonable to have specialized RCU implementations that provide only a subset of the RCU API, this is a bug in rcutorture. This commit therefore makes rcu_torture_fakewriter() check function pointers before invoking them, thus allowing it to test subsetted RCU implementations. Reported-by: Lihao Liang <lianglihao@huawei.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-20rcutorture: Abstract function and module namesPaul E. McKenney
This commit moves to __func__ for function names and for KBUILD_MODNAME for module names, all in the name of better resilience to change. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-20rcutorture: Replace multi-instance kzalloc() with kcalloc()Paul E. McKenney
This commit replaces array-allocation calls to kzalloc() with equivalent calls to kcalloc(). Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-20rcu: Remove SRCU throttlingPaul E. McKenney
The code in srcu_gp_end() inserts a delay every 0x3ff grace periods in order to prevent SRCU grace-period work from consuming an entire CPU when there is a long sequence of expedited SRCU grace-period requests. However, all of SRCU's grace-period work is carried out in workqueues, which are in turn within kthreads, which are automatically throttled as needed by the scheduler. In particular, if there is plenty of idle time, there is no point in throttling. This commit therefore removes the expedited SRCU grace-period throttling. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-20srcu: Remove dead code in srcu_gp_end()Byungchul Park
Of course, compilers will optimize out a dead code. Anyway, remove any dead code for better readibility. Signed-off-by: Byungchul Park <byungchul.park@lge.com> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-20srcu: Reduce scans of srcu_data in counter wrap checkIldar Ismagilov
Currently, given a multi-level srcu_node tree, SRCU can scan the full set of srcu_data structures at each level when cleaning up after a grace period. This, though harmless otherwise, represents pointless overhead. This commit therefore eliminates this overhead by scanning the srcu_data structures only when traversing the leaf srcu_node structures. Signed-off-by: Ildar Ismagilov <devix84@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-20srcu: Prevent sdp->srcu_gp_seq_needed_exp counter wrapIldar Ismagilov
SRCU checks each srcu_data structure's grace-period number for counter wrap four times per cycle by default. This frequency guarantees that normal comparisons will detect potential wrap. However, the expedited grace-period number is not checked. The consquences are not too horrible (a failure to expedite a grace period when requested), but it would be good to avoid such things. This commit therefore adds this check to the expedited grace-period number. Signed-off-by: Ildar Ismagilov <devix84@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-20srcu: Abstract function namePaul E. McKenney
This commit moves to __func__ for function names in the name of better resilience to change. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-20rcu: Make expedited RCU CPU selection avoid unnecessary storesPaul E. McKenney
This commit reworks the first loop in sync_rcu_exp_select_cpus() to avoid doing unnecssary stores to other CPUs' rcu_data structures. This speeds up that first loop by roughly a factor of two on an old x86 system. In the case where the system is mostly idle, this loop incurs a large fraction of the overhead of the synchronize_rcu_expedited(). There is less benefit on busy systems because the overhead of the smp_call_function_single() in the second loop dominates in that case. However, it is not unusual to do configuration chances involving RCU grace periods (both expedited and normal) while the system is mostly idle, so this optimization is worth doing. While we are in the area, this commit also adds parentheses to arguments used by the for_each_leaf_node_possible_cpu() macro. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-20rcu: Trace expedited GP delays due to transitioning CPUsPaul E. McKenney
If a CPU is transitioning to or from offline state, an expedited grace period may undergo a timed wait. This timed wait can unduly delay grace periods, so this commit adds a trace statement to make it visible. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-20rcu: Add more tracing of expedited grace periodsPaul E. McKenney
This commit adds more tracing of expedited grace periods to enable improved debugging of slowdowns. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-20rcu: Fix misprint in srcu_funnel_exp_startIldar Ismagilov
The srcu_funnel_exp_start() function checks to see if the srcu_struct structure's expedited grace period counter needs updating to reflect a newly arrived request for an expedited SRCU grace period. Unfortunately, the check is backwards, so this commit reverses the sense of the test. Signed-off-by: Ildar Ismagilov <devix84@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-20rcu: Fix init_rcu_head() comment.Paul E. McKenney
The current (and implicit) comment header for init_rcu_head() and destroy_rcu_head() incorrectly says that they are not needed for statically allocated rcu_head structures. This commit therefore fixes this comment. Reported-by: Bart Van Assche <Bart.VanAssche@wdc.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
2018-02-20rcu: Use wrapper for lockdep assertsMatthew Wilcox
Commits c0b334c5bfa9 and ea9b0c8a26a2 introduced new sparse warnings by accessing rcu_node->lock directly and ignoring the __private marker. Introduce a new wrapper and use it. Also fix a similar problem in srcutree.c introduced by a3883df3935e. Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-20rcu: Remove redundant nxttail index macro defineLiu, Changcheng
RCU's nxttail has been optimized to be a rcu_segcblist, which is a multi-tailed linked list with macros defined for the indexes for each tail. The indexes have been defined in linux/rcu_segcblist.h, so this commit removes the redundant definitions in kernel/rcu/tree.h. Signed-off-by: Liu Changcheng <changcheng.liu@intel.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-20rcu: Consolidate rcu.h #ifdefsPaul E. McKenney
The kernel/rcu/rcu.h file has a pair of consecutive #ifdefs on CONFIG_TINY_RCU, so this commit consolidates them, thus saving a few lines of code. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-20rcu: More clearly identify grace-period kthread stack dumpPaul E. McKenney
It is not always obvious that the stack dump from a starved grace-period kthread isn't instead that of a CPU stalling the current grace period. This commit therefore adds a pr_err() flagging these dumps. Reported-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-20rcu: Remove obsolete force-quiescent-state statistics for debugfsPaul E. McKenney
The debugfs interface displayed statistics on RCU-pending checks but this interface has since been removed. This commit therefore removes the no-longer-used rcu_state structure's ->n_force_qs_lh and ->n_force_qs_ngp fields along with their updates. (Though the ->n_force_qs_ngp field was actually not used at all, embarrassingly enough.) If this information proves necessary in the future, the corresponding event traces will be added. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-20rcu: Remove obsolete __rcu_pending() statistics for debugfsPaul E. McKenney
The debugfs interface displayed statistics on RCU-pending checks but this interface has since been removed. This commit therefore removes the no-longer-used rcu_data structure's ->n_rcu_pending, ->n_rp_core_needs_qs, ->n_rp_report_qs, ->n_rp_cb_ready, ->n_rp_cpu_needs_gp, ->n_rp_gp_completed, ->n_rp_gp_started, ->n_rp_nocb_defer_wakeup, and ->n_rp_need_nothing fields along with their updates. If this information proves necessary in the future, the corresponding event traces will be added. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-20rcu: Remove obsolete callback-invocation statistics for debugfsPaul E. McKenney
The debugfs interface displayed statistics on RCU callback invocation but this interface has since been removed. This commit therefore removes the no-longer-used rcu_data structure's ->n_cbs_invoked and ->n_nocbs_invoked fields along with their updates. If this information proves necessary in the future, the corresponding event traces will be added. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-20rcu: Remove obsolete boost statistics for debugfsPaul E. McKenney
The debugfs interface displayed statistics on RCU priority boosting, but this interface has since been removed. This commit therefore removes the no-longer-used rcu_data structure's ->n_tasks_boosted, ->n_exp_boosts, and ->n_exp_boosts and their updates. If this information proves necessary in the future, the corresponding event traces will be added. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-20rcu: Call touch_nmi_watchdog() while printing stall warningsTejun Heo
When RCU stall warning triggers, it can print out a lot of messages while holding spinlocks. If the console device is slow (e.g. an actual or IPMI serial console), it may end up triggering NMI hard lockup watchdog like the following. *** CPU printking while holding RCU spinlock PID: 4149739 TASK: ffff881a46baa880 CPU: 13 COMMAND: "CPUThreadPool8" #0 [ffff881fff945e48] crash_nmi_callback at ffffffff8103f7d0 #1 [ffff881fff945e58] nmi_handle at ffffffff81020653 #2 [ffff881fff945eb0] default_do_nmi at ffffffff81020c36 #3 [ffff881fff945ed0] do_nmi at ffffffff81020d32 #4 [ffff881fff945ef0] end_repeat_nmi at ffffffff81956a7e [exception RIP: io_serial_in+21] RIP: ffffffff81630e55 RSP: ffff881fff943b88 RFLAGS: 00000002 RAX: 000000000000ca00 RBX: ffffffff8230e188 RCX: 0000000000000000 RDX: 00000000000002fd RSI: 0000000000000005 RDI: ffffffff8230e188 RBP: ffff881fff943bb0 R8: 0000000000000000 R9: ffffffff820cb3c4 R10: 0000000000000019 R11: 0000000000002000 R12: 00000000000026e1 R13: 0000000000000020 R14: ffffffff820cd398 R15: 0000000000000035 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0000 --- <NMI exception stack> --- #5 [ffff881fff943b88] io_serial_in at ffffffff81630e55 #6 [ffff881fff943b90] wait_for_xmitr at ffffffff8163175c #7 [ffff881fff943bb8] serial8250_console_putchar at ffffffff816317dc #8 [ffff881fff943bd8] uart_console_write at ffffffff8162ac00 #9 [ffff881fff943c08] serial8250_console_write at ffffffff81634691 #10 [ffff881fff943c80] univ8250_console_write at ffffffff8162f7c2 #11 [ffff881fff943c90] console_unlock at ffffffff810dfc55 #12 [ffff881fff943cf0] vprintk_emit at ffffffff810dffb5 #13 [ffff881fff943d50] vprintk_default at ffffffff810e01bf #14 [ffff881fff943d60] vprintk_func at ffffffff810e1127 #15 [ffff881fff943d70] printk at ffffffff8119a8a4 #16 [ffff881fff943dd0] print_cpu_stall_info at ffffffff810eb78c #17 [ffff881fff943e88] rcu_check_callbacks at ffffffff810ef133 #18 [ffff881fff943ee8] update_process_times at ffffffff810f3497 #19 [ffff881fff943f10] tick_sched_timer at ffffffff81103037 #20 [ffff881fff943f38] __hrtimer_run_queues at ffffffff810f3f38 #21 [ffff881fff943f88] hrtimer_interrupt at ffffffff810f442b *** CPU triggering the hardlockup watchdog PID: 4149709 TASK: ffff88010f88c380 CPU: 26 COMMAND: "CPUThreadPool35" #0 [ffff883fff1059d0] machine_kexec at ffffffff8104a874 #1 [ffff883fff105a30] __crash_kexec at ffffffff811116cc #2 [ffff883fff105af0] __crash_kexec at ffffffff81111795 #3 [ffff883fff105b08] panic at ffffffff8119a6ae #4 [ffff883fff105b98] watchdog_overflow_callback at ffffffff81135dbd #5 [ffff883fff105bb0] __perf_event_overflow at ffffffff81186866 #6 [ffff883fff105be8] perf_event_overflow at ffffffff81192bc4 #7 [ffff883fff105bf8] intel_pmu_handle_irq at ffffffff8100b265 #8 [ffff883fff105df8] perf_event_nmi_handler at ffffffff8100489f #9 [ffff883fff105e58] nmi_handle at ffffffff81020653 #10 [ffff883fff105eb0] default_do_nmi at ffffffff81020b94 #11 [ffff883fff105ed0] do_nmi at ffffffff81020d32 #12 [ffff883fff105ef0] end_repeat_nmi at ffffffff81956a7e [exception RIP: queued_spin_lock_slowpath+248] RIP: ffffffff810da958 RSP: ffff883fff103e68 RFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000046 RCX: 00000000006d0000 RDX: ffff883fff49a950 RSI: 0000000000d10101 RDI: ffffffff81e54300 RBP: ffff883fff103e80 R8: ffff883fff11a950 R9: 0000000000000000 R10: 000000000e5873ba R11: 000000000000010f R12: ffffffff81e54300 R13: 0000000000000000 R14: ffff88010f88c380 R15: ffffffff81e54300 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 --- <NMI exception stack> --- #13 [ffff883fff103e68] queued_spin_lock_slowpath at ffffffff810da958 #14 [ffff883fff103e70] _raw_spin_lock_irqsave at ffffffff8195550b #15 [ffff883fff103e88] rcu_check_callbacks at ffffffff810eed18 #16 [ffff883fff103ee8] update_process_times at ffffffff810f3497 #17 [ffff883fff103f10] tick_sched_timer at ffffffff81103037 #18 [ffff883fff103f38] __hrtimer_run_queues at ffffffff810f3f38 #19 [ffff883fff103f88] hrtimer_interrupt at ffffffff810f442b --- <IRQ stack> --- Avoid spuriously triggering NMI hardlockup watchdog by touching it from the print functions. show_state_filter() shares the same problem and solution. v2: Relocate the comment to where it belongs. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-20doc: Fix typo in rcu_head commentsLihao Liang
Signed-off-by: Lihao Liang <lianglihao@huawei.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-20doc: Fix typo in rcutorture documentationLihao Liang
Signed-off-by: Lihao Liang <lianglihao@huawei.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-20rcu: Fix CPU offload boot message when no CPUs are offloadedPaul E. McKenney
In CONFIG_RCU_NOCB_CPU=y kernels, if the boot parameters indicate that none of the CPUs should in fact be offloaded, the following somewhat obtuse message appears: Offload RCU callbacks from CPUs: . This commit therefore makes the message at least grammatically correct in this case: Offload RCU callbacks from CPUs: (none) Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-15sched/isolation: Eliminate NO_HZ_FULL_ALLPaul E. McKenney
Commit 6f1982fedd59 ("sched/isolation: Handle the nohz_full= parameter") broke CONFIG_NO_HZ_FULL_ALL=y kernels. This breakage is due to the code under CONFIG_NO_HZ_FULL_ALL failing to invoke the shiny new housekeeping functions. This means that rcutorture scenario TREE04 now emits RCU CPU stall warnings due to the RCU grace-period kthreads not being awakened at a time of their choosing, or perhaps even not at all: [ 27.731422] rcu_bh kthread starved for 21001 jiffies! g18446744073709551369 c18446744073709551368 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x402 ->cpu=3 [ 27.731423] rcu_bh I14936 9 2 0x80080000 [ 27.731435] Call Trace: [ 27.731440] __schedule+0x31a/0x6d0 [ 27.731442] schedule+0x31/0x80 [ 27.731446] schedule_timeout+0x15a/0x320 [ 27.731453] ? call_timer_fn+0x130/0x130 [ 27.731457] rcu_gp_kthread+0x66c/0xea0 [ 27.731458] ? rcu_gp_kthread+0x66c/0xea0 Because no one has complained about CONFIG_NO_HZ_FULL_ALL=y being broken, I hypothesize that no one is in fact using it, other than rcutorture. This commit therefore eliminates CONFIG_NO_HZ_FULL_ALL and updates rcutorture's config files to instead use the nohz_full= kernel parameter to put the desired CPUs into nohz_full mode. Fixes: 6f1982fedd59 ("sched/isolation: Handle the nohz_full= parameter") Reported-by: kernel test robot <xiaolong.ye@intel.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Christoph Lameter <cl@linux.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Wanpeng Li <kernellwp@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: John Stultz <john.stultz@linaro.org> Cc: Jonathan Corbet <corbet@lwn.net>
2018-02-15rcu: Remove unnecessary spinlock in rcu_boot_init_percpu_data()Lihao Liang
Since rcu_boot_init_percpu_data() is only called at boot time, there is no data race and spinlock is not needed. Signed-off-by: Lihao Liang <lianglihao@huawei.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2018-02-11Linux 4.16-rc1v4.16-rc1Linus Torvalds
2018-02-11unify {de,}mangle_poll(), get rid of kernel-side POLL...Al Viro
except, again, POLLFREE and POLL_BUSY_LOOP. With this, we finally get to the promised end result: - POLL{IN,OUT,...} are plain integers and *not* in __poll_t, so any stray instances of ->poll() still using those will be caught by sparse. - eventpoll.c and select.c warning-free wrt __poll_t - no more kernel-side definitions of POLL... - userland ones are visible through the entire kernel (and used pretty much only for mangle/demangle) - same behavior as after the first series (i.e. sparc et.al. epoll(2) working correctly). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-11vfs: do bulk POLL* -> EPOLL* replacementLinus Torvalds
This is the mindless scripted replacement of kernel use of POLL* variables as described by Al, done by this script: for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'` for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done done with de-mangling cleanups yet to come. NOTE! On almost all architectures, the EPOLL* constants have the same values as the POLL* constants do. But they keyword here is "almost". For various bad reasons they aren't the same, and epoll() doesn't actually work quite correctly in some cases due to this on Sparc et al. The next patch from Al will sort out the final differences, and we should be all done. Scripted-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-11Merge branch 'work.poll2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull more poll annotation updates from Al Viro: "This is preparation to solving the problems you've mentioned in the original poll series. After this series, the kernel is ready for running for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'` for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done done as a for bulk search-and-replace. After that, the kernel is ready to apply the patch to unify {de,}mangle_poll(), and then get rid of kernel-side POLL... uses entirely, and we should be all done with that stuff. Basically, that's what you suggested wrt KPOLL..., except that we can use EPOLL... instead - they already are arch-independent (and equal to what is currently kernel-side POLL...). After the preparations (in this series) switch to returning EPOLL... from ->poll() instances is completely mechanical and kernel-side POLL... can go away. The last step (killing kernel-side POLL... and unifying {de,}mangle_poll() has to be done after the search-and-replace job, since we need userland-side POLL... for unified {de,}mangle_poll(), thus the cherry-pick at the last step. After that we will have: - POLL{IN,OUT,...} *not* in __poll_t, so any stray instances of ->poll() still using those will be caught by sparse. - eventpoll.c and select.c warning-free wrt __poll_t - no more kernel-side definitions of POLL... - userland ones are visible through the entire kernel (and used pretty much only for mangle/demangle) - same behavior as after the first series (i.e. sparc et.al. epoll(2) working correctly)" * 'work.poll2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: annotate ep_scan_ready_list() ep_send_events_proc(): return result via esed->res preparation to switching ->poll() to returning EPOLL... add EPOLLNVAL, annotate EPOLL... and event_poll->event use linux/poll.h instead of asm/poll.h xen: fix poll misannotation smc: missing poll annotations
2018-02-11Merge tag 'xtensa-20180211' of git://github.com/jcmvbkbc/linux-xtensaLinus Torvalds
Pull xtense fix from Max Filippov: "Build fix for xtensa architecture with KASAN enabled" * tag 'xtensa-20180211' of git://github.com/jcmvbkbc/linux-xtensa: xtensa: fix build with KASAN
2018-02-11Merge tag 'nios2-v4.16-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/lftan/nios2 Pull nios2 update from Ley Foon Tan: - clean up old Kconfig options from defconfig - remove leading 0x and 0s from bindings notation in dts files * tag 'nios2-v4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/lftan/nios2: nios2: defconfig: Cleanup from old Kconfig options nios2: dts: Remove leading 0x and 0s from bindings notation
2018-02-11xtensa: fix build with KASANMax Filippov
The commit 917538e212a2 ("kasan: clean up KASAN_SHADOW_SCALE_SHIFT usage") removed KASAN_SHADOW_SCALE_SHIFT definition from include/linux/kasan.h and added it to architecture-specific headers, except for xtensa. This broke the xtensa build with KASAN enabled. Define KASAN_SHADOW_SCALE_SHIFT in arch/xtensa/include/asm/kasan.h Reported by: kbuild test robot <fengguang.wu@intel.com> Fixes: 917538e212a2 ("kasan: clean up KASAN_SHADOW_SCALE_SHIFT usage") Acked-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2018-02-11nios2: defconfig: Cleanup from old Kconfig optionsKrzysztof Kozlowski
Remove old, dead Kconfig option INET_LRO. It is gone since commit 7bbf3cae65b6 ("ipv4: Remove inet_lro library"). Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Acked-by: Ley Foon Tan <ley.foon.tan@intel.com>
2018-02-11nios2: dts: Remove leading 0x and 0s from bindings notationMathieu Malaterre
Improve the DTS files by removing all the leading "0x" and zeros to fix the following dtc warnings: Warning (unit_address_format): Node /XXX unit name should not have leading "0x" and Warning (unit_address_format): Node /XXX unit name should not have leading 0s Converted using the following command: find . -type f \( -iname *.dts -o -iname *.dtsi \) -exec sed -E -i -e "s/@0x([0-9a-fA-F\.]+)\s?\{/@\L\1 \{/g" -e "s/@0+([0-9a-fA-F\.]+)\s?\{/@\L\1 \{/g" {} + For simplicity, two sed expressions were used to solve each warnings separately. To make the regex expression more robust a few other issues were resolved, namely setting unit-address to lower case, and adding a whitespace before the the opening curly brace: https://elinux.org/Device_Tree_Linux#Linux_conventions This is a follow up to commit 4c9847b7375a ("dt-bindings: Remove leading 0x from bindings notation") Reported-by: David Daney <ddaney@caviumnetworks.com> Suggested-by: Rob Herring <robh@kernel.org> Signed-off-by: Mathieu Malaterre <malat@debian.org> Acked-by: Ley Foon Tan <ley.foon.tan@intel.com>
2018-02-10Merge tag 'pci-v4.16-fixes-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci Pull PCI fix from Bjorn Helgaas: "Fix a POWER9/powernv INTx regression from the merge window (Alexey Kardashevskiy)" * tag 'pci-v4.16-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: powerpc/pci: Fix broken INTx configuration via OF
2018-02-10Merge tag 'for-linus-20180210' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block fixes from Jens Axboe: "A few fixes to round off the merge window on the block side: - a set of bcache fixes by way of Michael Lyle, from the usual bcache suspects. - add a simple-to-hook-into function for bpf EIO error injection. - fix blk-wbt that mischarectized flushes as reads. Improve the logic so that flushes and writes are accounted as writes, and only reads as reads. From me. - fix requeue crash in BFQ, from Paolo" * tag 'for-linus-20180210' of git://git.kernel.dk/linux-block: block, bfq: add requeue-request hook bcache: fix for data collapse after re-attaching an attached device bcache: return attach error when no cache set exist bcache: set writeback_rate_update_seconds in range [1, 60] seconds bcache: fix for allocator and register thread race bcache: set error_limit correctly bcache: properly set task state in bch_writeback_thread() bcache: fix high CPU occupancy during journal bcache: add journal statistic block: Add should_fail_bio() for bpf error injection blk-wbt: account flush requests correctly
2018-02-10Merge tag 'platform-drivers-x86-v4.16-3' of git://github.com/dvhart/linux-pdx86Linus Torvalds
Pull x86 platform driver updates from Darren Hart: "Mellanox fixes and new system type support. Mostly data for new system types with a correction and an uninitialized variable fix" [ Pulling from github because git.infradead.org currently seems to be down for some reason, but Darren had a backup location - Linus ] * tag 'platform-drivers-x86-v4.16-3' of git://github.com/dvhart/linux-pdx86: platform/x86: mlx-platform: Add support for new 200G IB and Ethernet systems platform/x86: mlx-platform: Add support for new msn201x system type platform/x86: mlx-platform: Add support for new msn274x system type platform/x86: mlx-platform: Fix power cable setting for msn21xx family platform/x86: mlx-platform: Add define for the negative bus platform/x86: mlx-platform: Use defines for bus assignment platform/mellanox: mlxreg-hotplug: Fix uninitialized variable