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2013-11-12Merge branch 'irq-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull IRQ changes from Ingo Molnar: "The biggest change this cycle are the softirq/hardirq stack interaction and nesting fixes, cleanups and reorganizations from Frederic. This is the longer followup story to the softirq nesting fix that is already upstream (commit ded797547548: "irq: Force hardirq exit's softirq processing on its own stack")" * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: irqchip: bcm2835: Convert to use IRQCHIP_DECLARE macro powerpc: Tell about irq stack coverage x86: Tell about irq stack coverage irq: Optimize softirq stack selection in irq exit irq: Justify the various softirq stack choices irq: Improve a bit softirq debugging irq: Optimize call to softirq on hardirq exit irq: Consolidate do_softirq() arch overriden implementations x86/irq: Correct comment about i8259 initialization
2013-11-12Merge branch 'core-rcu-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RCU updates from Ingo Molnar: "The main RCU changes in this cycle are: - Idle entry/exit changes, to throttle callback execution and other refinements to speed up kbuild, primarily to address performance issues located by Tibor Billes. - Grace-period related changes, primarily to aid in debugging, inspired by an -rt debugging session. - Code reorganization moving RCU's source files into its own kernel/rcu/ directory. - RCU documentation updates - Miscellaneous fixes. Note, the following commit: 5c889690aa08 mm: Place preemption point in do_mlockall() loop is identical to the commit already in your tree via email: 22356f447ceb mm: Place preemption point in do_mlockall() loop [ Your version of the changelog nicely demonstrates it how kernel oops messages should be trimmed properly :-/ ]" * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (30 commits) rcu: Move RCU-related source code to kernel/rcu directory rcu: Fix occurrence of "the the" in checklist.txt kthread: Add pointer to vmstat-avoidance patch rcu: Update stall-warning documentation rcu: Consistent rcu_is_watching() naming rcu: Change EXPORT_SYMBOL() to EXPORT_SYMBOL_GPL() rcu: Is it safe to enter an RCU read-side critical section? rcu: Throttle invoke_rcu_core() invocations due to non-lazy callbacks rcu: Throttle rcu_try_advance_all_cbs() execution rcu: Remove redundant code from rcu_cleanup_after_idle() rcu: Fix CONFIG_RCU_NOCB_CPU_ALL panic on machines with sparse CPU mask rcu: Avoid sparse warnings in rcu_nocb_wake trace event rcu: Track rcu_nocb_kthread()'s sleeping and awakening rcu: Distinguish between NOCB and non-NOCB rcu_callback trace events rcu: Add tracing for rcuo no-CBs CPU wakeup handshake rcu: Add tracing of normal (non-NOCB) grace-period requests rcu: Add tracing to rcu_gp_kthread() rcu: Flag lockless access to ->gp_flags with ACCESS_ONCE() rcu: Prevent spurious-wakeup DoS attack on rcu_gp_kthread() rcu: Improve grace-period start logic ...
2013-11-11tracing: Add rcu annotation for syscall trace descriptorsSteven Rostedt (Red Hat)
sparse complains about the enter/exit_sysycall_files[] variables being dereferenced with rcu_dereference_sched(). The fields need to be annotated with __rcu. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-11-11ftrace, sched: Add TRACE_FLAG_PREEMPT_RESCHEDPeter Zijlstra
Since the introduction of PREEMPT_NEED_RESCHED in: f27dde8deef3 ("sched: Add NEED_RESCHED to the preempt_count") we need to be able to look at both TIF_NEED_RESCHED and PREEMPT_NEED_RESCHED to understand the full preemption behaviour. Add it to the trace output. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Yuanhan Liu <yuanhan.liu@linux.intel.com> Link: http://lkml.kernel.org/r/20131004152826.GP3081@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-11stop_machine: Fix race between stop_two_cpus() and stop_cpus()Rik van Riel
There is a race between stop_two_cpus, and the global stop_cpus. It is possible for two CPUs to get their stopper functions queued "backwards" from one another, resulting in the stopper threads getting stuck, and the system hanging. This can happen because queuing up stoppers is not synchronized. This patch adds synchronization between stop_cpus (a rare operation), and stop_two_cpus. Reported-and-Tested-by: Prarit Bhargava <prarit@redhat.com> Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Mel Gorman <mgorman@suse.de> Link: http://lkml.kernel.org/r/20131101104146.03d1e043@annuminas.surriel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-11lockdep/proc: Fix lock-time avg computationPeter Zijlstra
> kernel/locking/lockdep_proc.c: In function 'seq_lock_time': > >> kernel/locking/lockdep_proc.c:424:23: warning: comparison of distinct pointer types lacks a cast [enabled by default] > > 418 static void seq_lock_time(struct seq_file *m, struct lock_time *lt) > 419 { > 420 seq_printf(m, "%14lu", lt->nr); > 421 seq_time(m, lt->min); > 422 seq_time(m, lt->max); > 423 seq_time(m, lt->total); > > 424 seq_time(m, lt->nr ? do_div(lt->total, lt->nr) : 0); > 425 } My compiler refuses to actually say that; but it looks wrong in that do_div() returns the remainder, not the divisor. Reported-by: Fengguang Wu <fengguang.wu@intel.com> Tested-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Davidlohr Bueso <davidlohr@hp.com> Link: http://lkml.kernel.org/r/20131106164230.GE16117@laptop.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-11locking/doc: Update references to kernel/mutex.cPeter Zijlstra
Fix this docbook error: >> docproc: kernel/mutex.c: No such file or directory by updating the stale references to kernel/mutex.c. Reported-by: fengguang.wu@intel.com Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-34pikw1tlsskj65rrt5iusrq@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-09uprobes: Fix the memory out of bound overwrite in copy_insn()Oleg Nesterov
1. copy_insn() doesn't look very nice, all calculations are confusing and it is not immediately clear why do we read the 2nd page first. 2. The usage of inode->i_size is wrong on 32-bit machines. 3. "Instruction at end of binary" logic is simply wrong, it doesn't handle the case when uprobe->offset > inode->i_size. In this case "bytes" overflows, and __copy_insn() writes to the memory outside of uprobe->arch.insn. Yes, uprobe_register() checks i_size_read(), but this file can be truncated after that. All i_size checks are racy, we do this only to catch the obvious mistakes. Change copy_insn() to call __copy_insn() in a loop, simplify and fix the bytes/nbytes calculations. Note: we do not care if we read extra bytes after inode->i_size if we got the valid page. This is fine because the task gets the same page after page-fault, and arch_uprobe_analyze_insn() can't know how many bytes were actually read anyway. Signed-off-by: Oleg Nesterov <oleg@redhat.com>
2013-11-09uprobes: Fix the wrong usage of current->utask in uprobe_copy_process()Oleg Nesterov
Commit aa59c53fd459 "uprobes: Change uprobe_copy_process() to dup xol_area" has a stupid typo, we need to setup t->utask->vaddr but the code wrongly uses current->utask. Even with this bug dup_xol_work() works "in practice", but only because get_unmapped_area(NULL, TASK_SIZE - PAGE_SIZE) likely returns the same address every time. Signed-off-by: Oleg Nesterov <oleg@redhat.com>
2013-11-09constify copy_siginfo_to_user{,32}()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09switch elf_core_write_extra_phdrs() to dump_emit()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-08Merge branch 'blk-mq/core' into for-3.13/coreJens Axboe
Signed-off-by: Jens Axboe <axboe@kernel.dk> Conflicts: block/blk-timeout.c
2013-11-08kernel: trace: blktrace: remove redundent memcpy() in compat_blk_trace_setup()Chen Gang
do_blk_trace_setup() will fully initialize 'buts.name', so can remove the related memcpy(). And also use BLKTRACE_BDEV_SIZE and ARRAY_SIZE instead of hard code number '32'. Signed-off-by: Chen Gang <gang.chen@asianux.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-11-08blktrace: Send BLK_TN_PROCESS events to all running tracesJan Kara
Currently each task sends BLK_TN_PROCESS event to the first traced device it interacts with after a new trace is started. When there are several traced devices and the task accesses more devices, this logic can result in BLK_TN_PROCESS being sent several times to some devices while it is never sent to other devices. Thus blkparse doesn't display command name when parsing some blktrace files. Fix the problem by sending BLK_TN_PROCESS event to all traced devices when a task interacts with any of them. Signed-off-by: Jan Kara <jack@suse.cz> Review-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-11-08Merge tag 'ftrace-urgent-3.12-v2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull perf/ftrace fix from Steven Rostedt: "Dave Jones's trinity program was able to enable the function tracer from a normal user account via the perf syscall "perf_event_open()". When I was able to reproduce it with trinity, I was able to track down exactly how it happened. I discovered that the check for whether the function tracepoint should be activated or not was using the "perf_paranoid_kernel()" check which by default, lets the user continue. The user should not by default be able to enable function tracing. The fix is to use "perf_paranoid_tracepoint_raw()" which will not let the user enable function tracing. This is a security fix as normal users should never be allowed to enable the function tracer" * tag 'ftrace-urgent-3.12-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: perf/ftrace: Fix paranoid level for enabling function tracer
2013-11-07Merge branch 'pm-sleep'Rafael J. Wysocki
* pm-sleep: PM / hibernate: Avoid overflow in hibernate_preallocate_memory()
2013-11-07Merge tag 'tty-3.13-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial driver updates from Greg KH: "Here's the big tty/serial driver update for 3.13-rc1. There's some more minor n_tty work here, but nothing like previous kernel releases. Also some new driver ids, driver updates for new hardware, and other small things. All of this has been in linux-next for a while with no issues" * tag 'tty-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (84 commits) serial: omap: fix missing comma serial: sh-sci: Enable the driver on all ARM platforms serial: mfd: Staticize local symbols serial: omap: fix a few checkpatch warnings serial: omap: improve RS-485 performance mrst_max3110: fix unbalanced IRQ issue during resume serial: omap: Add support for optional wake-up serial: sirf: remove duplicate defines tty: xuartps: Fix build error when COMMON_CLK is not set tty: xuartps: Fix build error due to missing forward declaration tty: xuartps: Fix "may be used uninitialized" build warning serial: 8250_pci: add Pericom PCIe Serial board Support (12d8:7952/4/8) - Chip PI7C9X7952/4/8 tty: xuartps: Update copyright information tty: xuartps: Implement suspend/resume callbacks tty: xuartps: Dynamically adjust to input frequency changes tty: xuartps: Updating set_baud_rate() tty: xuartps: Force enable the UART in xuartps_console_write tty: xuartps: support 64 byte FIFO size tty: xuartps: Add polled mode support for xuartps tty: xuartps: Implement BREAK detection, add SYSRQ support ...
2013-11-07Merge tag 'driver-core-3.13-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core / sysfs patches from Greg KH: "Here's the big driver core / sysfs update for 3.13-rc1. There's lots of dev_groups updates for different subsystems, as they all get slowly migrated over to the safe versions of the attribute groups (removing userspace races with the creation of the sysfs files.) Also in here are some kobject updates, devres expansions, and the first round of Tejun's sysfs reworking to enable it to be used by other subsystems as a backend for an in-kernel filesystem. All of these have been in linux-next for a while with no reported issues" * tag 'driver-core-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (83 commits) sysfs: rename sysfs_assoc_lock and explain what it's about sysfs: use generic_file_llseek() for sysfs_file_operations sysfs: return correct error code on unimplemented mmap() mdio_bus: convert bus code to use dev_groups device: Make dev_WARN/dev_WARN_ONCE print device as well as driver name sysfs: separate out dup filename warning into a separate function sysfs: move sysfs_hash_and_remove() to fs/sysfs/dir.c sysfs: remove unused sysfs_get_dentry() prototype sysfs: honor bin_attr.attr.ignore_lockdep sysfs: merge sysfs_elem_bin_attr into sysfs_elem_attr devres: restore zeroing behavior of devres_alloc() sysfs: fix sysfs_write_file for bin file input: gameport: convert bus code to use dev_groups input: serio: remove bus usage of dev_attrs input: serio: use DEVICE_ATTR_RO() i2o: convert bus code to use dev_groups memstick: convert bus code to use dev_groups tifm: convert bus code to use dev_groups virtio: convert bus code to use dev_groups ipack: convert bus code to use dev_groups ...
2013-11-07PM / hibernate: Avoid overflow in hibernate_preallocate_memory()Aaron Lu
When system has a lot of highmem (e.g. 16GiB using a 32 bits kernel), the code to calculate how much memory we need to preallocate in normal zone may cause overflow. As Leon has analysed: It looks that during computing 'alloc' variable there is overflow: alloc = (3943404 - 1970542) - 1978280 = -5418 (signed) And this function goes to err_out. Fix this by avoiding that overflow. References: https://bugzilla.kernel.org/show_bug.cgi?id=60817 Reported-and-tested-by: Leon Drugi <eyak@wp.pl> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Aaron Lu <aaron.lu@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-11-06tracing: Do not use signed enums with unsigned long long in fgragh outputSteven Rostedt (Red Hat)
The duration field of print_graph_duration() can also be used to do the space filling by passing an enum in it: DURATION_FILL_FULL DURATION_FILL_START DURATION_FILL_END The problem is that these are enums and defined as negative, but the duration field is unsigned long long. Most archs are fine with this but blackfin fails to compile because of it: kernel/built-in.o: In function `print_graph_duration': kernel/trace/trace_functions_graph.c:782: undefined reference to `__ucmpdi2' Overloading a unsigned long long with an signed enum is just bad in principle. We can accomplish the same thing by using part of the flags field instead. Cc: Mike Frysinger <vapier@gentoo.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-11-06tracing: Remove unused function ftrace_off_permanent()Steven Rostedt (Red Hat)
In the past, ftrace_off_permanent() was called if something strange was detected. But the ftrace_bug() now handles all the anomolies that can happen with ftrace (function tracing), and there are no uses of ftrace_off_permanent(). Get rid of it. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-11-06tracing: Do not assign filp->private_data to freed memoryGeyslan G. Bem
In system_tr_open(), the filp->private_data can be assigned the 'dir' variable even if it was freed. This is on the error path, and is harmless because the error return code will prevent filp->private_data from being used. But for correctness, we should not assign it to a recently freed variable, as that can cause static tools to give false warnings. Also have both subsystem_open() and system_tr_open() return -ENODEV if tracing has been disabled. Link: http://lkml.kernel.org/r/1383764571-7318-1-git-send-email-geyslan@gmail.com Signed-off-by: Geyslan G. Bem <geyslan@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-11-06perf/ftrace: Fix paranoid level for enabling function tracerSteven Rostedt
The current default perf paranoid level is "1" which has "perf_paranoid_kernel()" return false, and giving any operations that use it, access to normal users. Unfortunately, this includes function tracing and normal users should not be allowed to enable function tracing by default. The proper level is defined at "-1" (full perf access), which "perf_paranoid_tracepoint_raw()" will only give access to. Use that check instead for enabling function tracing. Reported-by: Dave Jones <davej@redhat.com> Reported-by: Vince Weaver <vincent.weaver@maine.edu> Tested-by: Vince Weaver <vincent.weaver@maine.edu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: stable@vger.kernel.org # 3.4+ CVE: CVE-2013-2930 Fixes: ced39002f5ea ("ftrace, perf: Add support to use function tracepoint in perf") Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-11-06uprobes: Export write_opcode() as uprobe_write_opcode()Oleg Nesterov
set_swbp() and set_orig_insn() are __weak, but this is pointless because write_opcode() is static. Export write_opcode() as uprobe_write_opcode() for the upcoming arm port, this way it can actually override set_swbp() and use __opcode_to_mem_arm(bpinsn) instead if UPROBE_SWBP_INSN. Signed-off-by: Oleg Nesterov <oleg@redhat.com>
2013-11-06uprobes: Introduce arch_uprobe->ixolOleg Nesterov
Currently xol_get_insn_slot() assumes that we should simply copy arch_uprobe->insn[] which is (ignoring arch_uprobe_analyze_insn) just the copy of the original insn. This is not true for arm which needs to create another insn to execute it out-of-line. So this patch simply adds the new member, ->ixol into the union. This doesn't make any difference for x86 and powerpc, but arm can divorce insn/ixol and initialize the correct xol insn in arch_uprobe_analyze_insn(). Signed-off-by: Oleg Nesterov <oleg@redhat.com>
2013-11-06uprobes: Kill module_init() and module_exit()Oleg Nesterov
Turn module_init() into __initcall() and kill module_exit(). This code can't be compiled as a module so these module_*() calls only add the confusion, especially if arch-dependant code needs its own initialization hooks. Signed-off-by: Oleg Nesterov <oleg@redhat.com>
2013-11-06audit: fix type of sessionid in audit_set_loginuid()Eric Paris
sfr pointed out that with CONFIG_UIDGID_STRICT_TYPE_CHECKS set the audit tree would not build. This is because the oldsessionid in audit_set_loginuid() was accidentally being declared as a kuid_t. This patch fixes that declaration mistake. Example of problem: kernel/auditsc.c: In function 'audit_set_loginuid': kernel/auditsc.c:2003:15: error: incompatible types when assigning to type 'kuid_t' from type 'int' oldsessionid = audit_get_sessionid(current); Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Eric Paris <eparis@redhat.com>
2013-11-06tracing: Add helper function tracing_is_disabled()Geyslan G. Bem
This patch creates the function 'tracing_is_disabled', which can be used outside of trace.c. Link: http://lkml.kernel.org/r/1382141754-12155-1-git-send-email-geyslan@gmail.com Signed-off-by: Geyslan G. Bem <geyslan@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-11-06tracing: Open tracer when ftrace_dump_on_oops is usedCody P Schafer
With ftrace_dump_on_oops, we previously did not open the tracer in question, sometimes causing the trace output to be useless. For example, the function_graph tracer with tracing_thresh set dumped via ftrace_dump_on_oops would show a series of '}' indented at different levels, but no function names. call trace->open() (and do a few other fixups copied from the normal dump path) to make the output more intelligible. Link: http://lkml.kernel.org/r/1382554197-16961-1-git-send-email-cody@linux.vnet.ibm.com Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-11-06sched: Remove unnecessary iteration over sched domains to update nr_busy_cpusPreeti U Murthy
nr_busy_cpus parameter is used by nohz_kick_needed() to find out the number of busy cpus in a sched domain which has SD_SHARE_PKG_RESOURCES flag set. Therefore instead of updating nr_busy_cpus at every level of sched domain, since it is irrelevant, we can update this parameter only at the parent domain of the sd which has this flag set. Introduce a per-cpu parameter sd_busy which represents this parent domain. In nohz_kick_needed() we directly query the nr_busy_cpus parameter associated with the groups of sd_busy. By associating sd_busy with the highest domain which has SD_SHARE_PKG_RESOURCES flag set, we cover all lower level domains which could have this flag set and trigger nohz_idle_balancing if any of the levels have more than one busy cpu. sd_busy is irrelevant for asymmetric load balancing. However sd_asym has been introduced to represent the highest sched domain which has SD_ASYM_PACKING flag set so that it can be queried directly when required. While we are at it, we might as well change the nohz_idle parameter to be updated at the sd_busy domain level alone and not the base domain level of a CPU. This will unify the concept of busy cpus at just one level of sched domain where it is currently used. Signed-off-by: Preeti U Murthy<preeti@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: svaidy@linux.vnet.ibm.com Cc: vincent.guittot@linaro.org Cc: bitbucket@online.de Cc: benh@kernel.crashing.org Cc: anton@samba.org Cc: Morten.Rasmussen@arm.com Cc: pjt@google.com Cc: peterz@infradead.org Cc: mikey@neuling.org Link: http://lkml.kernel.org/r/20131030031252.23426.4417.stgit@preeti.in.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06sched: Fix asymmetric scheduling for POWER7Vaidyanathan Srinivasan
Asymmetric scheduling within a core is a scheduler loadbalancing feature that is triggered when SD_ASYM_PACKING flag is set. The goal for the load balancer is to move tasks to lower order idle SMT threads within a core on a POWER7 system. In nohz_kick_needed(), we intend to check if our sched domain (core) is completely busy or we have idle cpu. The following check for SD_ASYM_PACKING: (cpumask_first_and(nohz.idle_cpus_mask, sched_domain_span(sd)) < cpu) already covers the case of checking if the domain has an idle cpu, because cpumask_first_and() will not yield any set bits if this domain has no idle cpu. Hence, nr_busy check against group weight can be removed. Reported-by: Michael Neuling <michael.neuling@au1.ibm.com> Signed-off-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Signed-off-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Tested-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: vincent.guittot@linaro.org Cc: bitbucket@online.de Cc: benh@kernel.crashing.org Cc: anton@samba.org Cc: Morten.Rasmussen@arm.com Cc: pjt@google.com Link: http://lkml.kernel.org/r/20131030031242.23426.13019.stgit@preeti.in.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06perf: Factor out strncpy() in perf_event_mmap_event()Oleg Nesterov
While this is really minor, but strncpy() does the unnecessary zero-padding till the end of tmp[16] and it is called every time we are going to use the string literal. Turn these strncpy()'s into the single strlcpy() under the new label, saves 72 bytes. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20131017182417.GA17753@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06perf: Fix arch_perf_out_copy_user defaultPeter Zijlstra
The arch_perf_output_copy_user() default of __copy_from_user_inatomic() returns bytes not copied, while all other argument functions given DEFINE_OUTPUT_COPY() return bytes copied. Since copy_from_user_nmi() is the odd duck out by returning bytes copied where all other *copy_{to,from}* functions return bytes not copied, change it over and ammend DEFINE_OUTPUT_COPY() to expect bytes not copied. Oddly enough DEFINE_OUTPUT_COPY() already returned bytes not copied while expecting its worker functions to return bytes copied. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: will.deacon@arm.com Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20131030201622.GR16117@laptop.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06perf: Update a stale commentPeter Zijlstra
Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Michael Ellerman <michael@ellerman.id.au> Cc: Michael Neuling <mikey@neuling.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: james.hogan@imgtec.com Cc: Vince Weaver <vince@deater.net> Cc: Victor Kaplansky <VICTORK@il.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Anton Blanchard <anton@samba.org> Link: http://lkml.kernel.org/n/tip-9s5mze78gmlz19agt39i8rii@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06perf: Optimize perf_output_begin() -- address calculationPeter Zijlstra
Rewrite the handle address calculation code to be clearer. Saves 8 bytes on x86_64-defconfig. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Michael Ellerman <michael@ellerman.id.au> Cc: Michael Neuling <mikey@neuling.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: james.hogan@imgtec.com Cc: Vince Weaver <vince@deater.net> Cc: Victor Kaplansky <VICTORK@il.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Anton Blanchard <anton@samba.org> Link: http://lkml.kernel.org/n/tip-3trb2n2henb9m27tncef3ag7@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06perf: Optimize perf_output_begin() -- lost_event casePeter Zijlstra
Avoid touching the lost_event and sample_data cachelines twince. Its not like we end up doing less work, but it might help to keep all accesses to these cachelines in one place. Due to code shuffle, this looses 4 bytes on x86_64-defconfig. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Michael Ellerman <michael@ellerman.id.au> Cc: Michael Neuling <mikey@neuling.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: james.hogan@imgtec.com Cc: Vince Weaver <vince@deater.net> Cc: Victor Kaplansky <VICTORK@il.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Anton Blanchard <anton@samba.org> Link: http://lkml.kernel.org/n/tip-zfxnc58qxj0eawdoj31hhupv@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06perf: Optimize perf_output_begin()Peter Zijlstra
There's no point in re-doing the memory-barrier when we fail the cmpxchg(). Also placing it after the space reservation loop makes it clearer it only separates the userpage->tail read from the data stores. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Michael Ellerman <michael@ellerman.id.au> Cc: Michael Neuling <mikey@neuling.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: james.hogan@imgtec.com Cc: Vince Weaver <vince@deater.net> Cc: Victor Kaplansky <VICTORK@il.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Anton Blanchard <anton@samba.org> Link: http://lkml.kernel.org/n/tip-c19u6egfldyx86tpyc3zgkw9@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06perf: Add unlikely() to the ring-buffer codePeter Zijlstra
Add unlikely() annotations to 'slow' paths: When having a sampling event but no output buffer; you have bigger issues -- also the bail is still faster than actually doing the work. When having a sampling event but a control page only buffer, you have bigger issues -- again the bail is still faster than actually doing work. Optimize for the case where you're not loosing events -- again, not doing the work is still faster but make sure that when you have to actually do work its as fast as possible. The typical watermark is 1/2 the buffer size, so most events will not take this path. Shrinks perf_output_begin() by 16 bytes on x86_64-defconfig. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Michael Ellerman <michael@ellerman.id.au> Cc: Michael Neuling <mikey@neuling.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: james.hogan@imgtec.com Cc: Vince Weaver <vince@deater.net> Cc: Victor Kaplansky <VICTORK@il.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Anton Blanchard <anton@samba.org> Link: http://lkml.kernel.org/n/tip-wlg3jew3qnutm8opd0hyeuwn@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06perf: Simplify the ring-buffer codePeter Zijlstra
By using CIRC_SPACE() we can obviate the need for perf_output_space(). Shrinks the size of perf_output_begin() by 17 bytes on x86_64-defconfig. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Michael Ellerman <michael@ellerman.id.au> Cc: Michael Neuling <mikey@neuling.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: james.hogan@imgtec.com Cc: Vince Weaver <vince@deater.net> Cc: Victor Kaplansky <VICTORK@il.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Anton Blanchard <anton@samba.org> Link: http://lkml.kernel.org/n/tip-vtb0xb0llebmsdlfn1v5vtfj@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06locking: Move the percpu-rwsem code to kernel/locking/Peter Zijlstra
Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-52bjmtty46we26hbfd9sc9iy@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06locking: Move the lglocks code to kernel/locking/Peter Zijlstra
Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-amd6pg1mif6tikbyktfvby3y@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06locking: Move the rwsem code to kernel/locking/Peter Zijlstra
Notably: changed lib/rwsem* targets from lib- to obj-, no idea about the ramifications of that. Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-g0kynfh5feriwc6p3h6kpbw6@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06locking: Move the rtmutex code to kernel/locking/Peter Zijlstra
Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-p9ijt8div0hwldexwfm4nlhj@git.kernel.org [ Fixed build failure in kernel/rcu/tree_plugin.h. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06hung_task: add method to reset detectorMarcelo Tosatti
In certain occasions it is possible for a hung task detector positive to be false: continuation from a paused VM, for example. Add a method to reset detection, similar as is done with other kernel watchdogs. Acked-by: Don Zickus <dzickus@redhat.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-11-06locking: Move the semaphore core to kernel/locking/Peter Zijlstra
Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-vmw5sf6vzmua1z6nx1cg69h2@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06locking: Move the spinlock code to kernel/locking/Peter Zijlstra
Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-b81ol0z3mon45m51o131yc9j@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06locking: Move the lockdep code to kernel/locking/Peter Zijlstra
Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-wl7s3tta5isufzfguc23et06@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06locking: Move the mutex code to kernel/locking/Peter Zijlstra
Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-1ditvncg30dgbpvrz2bxfmke@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06Merge branch 'sched/core' into core/locking, to prepare the kernel/locking/ ↵Ingo Molnar
file move Conflicts: kernel/Makefile There are conflicts in kernel/Makefile due to file moving in the scheduler tree - resolve them. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-11-06sched: Move completion code from core.c to completion.cPeter Zijlstra
Completions already have their own header file: linux/completion.h Move the implementation out of kernel/sched/core.c and into its own file: kernel/sched/completion.c. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-x2y49rmxu5dljt66ai2lcfuw@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>