user/sven/linux.git/kernel/events, branch v3.7

perf, powerpc: Fix hw breakpoints returning -ENOSPC

2012-10-30T09:07:58Z

I've been trying to get hardware breakpoints with perf to work on POWER7 but I'm getting the following: % perf record -e mem:0x10000000 true Error: sys_perf_event_open() syscall returned with 28 (No space left on device). /bin/dmesg may provide additional information. Fatal: No CONFIG_PERF_EVENTS=y kernel support configured? true: Terminated (FWIW adding -a and it works fine) Debugging it seems that __reserve_bp_slot() is returning ENOSPC because it thinks there are no free breakpoint slots on this CPU. I have a 2 CPUs, so perf userspace is doing two perf_event_open syscalls to add a counter to each CPU [1]. The first syscall succeeds but the second is failing. On this second syscall, fetch_bp_busy_slots() sets slots.pinned to be 1, despite there being no breakpoint on this CPU. This is because the call the task_bp_pinned, checks all CPUs, rather than just the current CPU. POWER7 only has one hardware breakpoint per CPU (ie. HBP_NUM=1), so we return ENOSPC. The following patch fixes this by checking the associated CPU for each breakpoint in task_bp_pinned. I'm not familiar with this code, so it's provided as a reference to the above issue. Signed-off-by: Michael Neuling Acked-by: Peter Zijlstra Cc: Michael Ellerman Cc: Jovi Zhang Cc: K Prasad Link: http://lkml.kernel.org/r/1351268936-2956-1-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar

Merge branch 'uprobes/core' of git://git.kernel.org/pub/scm/linux/kernel/git/oleg/misc into perf/urgent

2012-10-21T16:18:17Z

Pull various uprobes bugfixes from Oleg Nesterov - mostly race and failure path fixes. Signed-off-by: Ingo Molnar

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

2012-10-13T01:20:11Z

Pull perf updates from Ingo Molnar: "This tree includes some late late perf items that missed the first round: tools: - Bash auto completion improvements, now we can auto complete the tools long options, tracepoint event names, etc, from Namhyung Kim. - Look up thread using tid instead of pid in 'perf sched'. - Move global variables into a perf_kvm struct, from David Ahern. - Hists refactorings, preparatory for improved 'diff' command, from Jiri Olsa. - Hists refactorings, preparatory for event group viewieng work, from Namhyung Kim. - Remove double negation on optional feature macro definitions, from Namhyung Kim. - Remove several cases of needless global variables, on most builtins. - misc fixes kernel: - sysfs support for IBS on AMD CPUs, from Robert Richter. - Support for an upcoming Intel CPU, the Xeon-Phi / Knights Corner HPC blade PMU, from Vince Weaver. - misc fixes" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (46 commits) perf: Fix perf_cgroup_switch for sw-events perf: Clarify perf_cpu_context::active_pmu usage by renaming it to ::unique_pmu perf/AMD/IBS: Add sysfs support perf hists: Add more helpers for hist entry stat perf hists: Move he->stat.nr_events initialization to a template perf hists: Introduce struct he_stat perf diff: Removing the total_period argument from output code perf tool: Add hpp interface to enable/disable hpp column perf tools: Removing hists pair argument from output path perf hists: Separate overhead and baseline columns perf diff: Refactor diff displacement possition info perf hists: Add struct hists pointer to struct hist_entry perf tools: Complete tracepoint event names perf/x86: Add support for Intel Xeon-Phi Knights Corner PMU perf evlist: Remove some unused methods perf evlist: Introduce add_newtp method perf kvm: Move global variables into a perf_kvm struct perf tools: Convert to BACKTRACE_SUPPORT perf tools: Long option completion support for each subcommands perf tools: Complete long option names of perf command ...

mm: wrap calls to set_pte_at_notify with invalidate_range_start and invalidate_range_end

2012-10-09T07:22:58Z

In order to allow sleeping during invalidate_page mmu notifier calls, we need to avoid calling when holding the PT lock. In addition to its direct calls, invalidate_page can also be called as a substitute for a change_pte call, in case the notifier client hasn't implemented change_pte. This patch drops the invalidate_page call from change_pte, and instead wraps all calls to change_pte with invalidate_range_start and invalidate_range_end calls. Note that change_pte still cannot sleep after this patch, and that clients implementing change_pte should not take action on it in case the number of outstanding invalidate_range_start calls is larger than one, otherwise they might miss a later invalidation. Signed-off-by: Haggai Eran Cc: Andrea Arcangeli Cc: Sagi Grimberg Cc: Peter Zijlstra Cc: Xiao Guangrong Cc: Or Gerlitz Cc: Haggai Eran Cc: Shachar Raindel Cc: Liran Liss Cc: Christoph Lameter Cc: Avi Kivity Cc: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: replace vma prio_tree with an interval tree

2012-10-09T07:22:39Z

Implement an interval tree as a replacement for the VMA prio_tree. The algorithms are similar to lib/interval_tree.c; however that code can't be directly reused as the interval endpoints are not explicitly stored in the VMA. So instead, the common algorithm is moved into a template and the details (node type, how to get interval endpoints from the node, etc) are filled in using the C preprocessor. Once the interval tree functions are available, using them as a replacement to the VMA prio tree is a relatively simple, mechanical job. Signed-off-by: Michel Lespinasse Cc: Rik van Riel Cc: Hillf Danton Cc: Peter Zijlstra Cc: Catalin Marinas Cc: Andrea Arcangeli Cc: David Woodhouse Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: kill vma flag VM_RESERVED and mm->reserved_vm counter

2012-10-09T07:22:19Z

A long time ago, in v2.4, VM_RESERVED kept swapout process off VMA, currently it lost original meaning but still has some effects: | effect | alternative flags -+------------------------+--------------------------------------------- 1| account as reserved_vm | VM_IO 2| skip in core dump | VM_IO, VM_DONTDUMP 3| do not merge or expand | VM_IO, VM_DONTEXPAND, VM_HUGETLB, VM_PFNMAP 4| do not mlock | VM_IO, VM_DONTEXPAND, VM_HUGETLB, VM_PFNMAP This patch removes reserved_vm counter from mm_struct. Seems like nobody cares about it, it does not exported into userspace directly, it only reduces total_vm showed in proc. Thus VM_RESERVED can be replaced with VM_IO or pair VM_DONTEXPAND | VM_DONTDUMP. remap_pfn_range() and io_remap_pfn_range() set VM_IO|VM_DONTEXPAND|VM_DONTDUMP. remap_vmalloc_range() set VM_DONTEXPAND | VM_DONTDUMP. [akpm@linux-foundation.org: drivers/vfio/pci/vfio_pci.c fixup] Signed-off-by: Konstantin Khlebnikov Cc: Alexander Viro Cc: Carsten Otte Cc: Chris Metcalf Cc: Cyrill Gorcunov Cc: Eric Paris Cc: H. Peter Anvin Cc: Hugh Dickins Cc: Ingo Molnar Cc: James Morris Cc: Jason Baron Cc: Kentaro Takeda Cc: Matt Helsley Cc: Nick Piggin Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Robert Richter Cc: Suresh Siddha Cc: Tetsuo Handa Cc: Venkatesh Pallipadi Acked-by: Linus Torvalds Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

uprobes: Fix the racy uprobe->flags manipulation

2012-10-07T19:19:43Z

Multiple threads can manipulate uprobe->flags, this is obviously unsafe. For example mmap can set UPROBE_COPY_INSN while register tries to set UPROBE_RUN_HANDLER, the latter can also race with can_skip_sstep() which clears UPROBE_SKIP_SSTEP. Change this code to use bitops. Signed-off-by: Oleg Nesterov Acked-by: Srikar Dronamraju

uprobes: Fix prepare_uprobe() race with itself

2012-10-07T19:19:43Z

install_breakpoint() is called under mm->mmap_sem, this protects set_swbp() but not prepare_uprobe(). Two or more different tasks can call install_breakpoint()->prepare_uprobe() at the same time, this leads to numerous problems if UPROBE_COPY_INSN is not set. Just for example, the second copy_insn() can corrupt the already analyzed/fixuped uprobe->arch.insn and race with handle_swbp(). This patch simply adds uprobe->copy_mutex to serialize this code. We could probably reuse ->consumer_rwsem, but this would mean that consumer->handler() can not use mm->mmap_sem, not good. Note: this is another temporary ugly hack until we move this logic into uprobe_register(). Signed-off-by: Oleg Nesterov Acked-by: Srikar Dronamraju

uprobes: Introduce prepare_uprobe()

2012-10-07T19:19:42Z

Preparation. Extract the copy_insn/arch_uprobe_analyze_insn code from install_breakpoint() into the new helper, prepare_uprobe(). And move uprobe->flags defines from uprobes.h to uprobes.c, nobody else can use them anyway. Signed-off-by: Oleg Nesterov Acked-by: Srikar Dronamraju

uprobes: Fix handle_swbp() vs unregister() + register() race

2012-10-07T19:19:41Z

Strictly speaking this race was added by me in 56bb4cf6. However I think that this bug is just another indication that we should move copy_insn/uprobe_analyze_insn code from install_breakpoint() to uprobe_register(), there are a lot of other reasons for that. Until then, add a hack to close the race. A task can hit uprobe U1, but before it calls find_uprobe() this uprobe can be unregistered *AND* another uprobe U2 can be added to uprobes_tree at the same inode/offset. In this case handle_swbp() will use the not-fully-initialized U2, in particular its arch.insn for xol. Add the additional !UPROBE_COPY_INSN check into handle_swbp(), if this flag is not set we simply restart as if the new uprobe was not inserted yet. This is not very nice, we need barriers, but we will remove this hack when we change uprobe_register(). Note: with or without this patch install_breakpoint() can race with itself, yet another reson to kill UPROBE_COPY_INSN altogether. And even the usage of uprobe->flags is not safe. See the next patches. Signed-off-by: Oleg Nesterov Acked-by: Srikar Dronamraju