kernel.git/arch/powerpc/perf, branch linux-3.17.y

powerpc/perf: Fix ABIv2 kernel backtraces

2014-09-09T09:02:45Z

ABIv2 kernels are failing to backtrace through the kernel. An example: 39.30% readseek2_proce [kernel.kallsyms] [k] find_get_entry | --- find_get_entry __GI___libc_read The problem is in valid_next_sp() where we check that the new stack pointer is at least STACK_FRAME_OVERHEAD below the previous one. ABIv1 has a minimum stack frame size of 112 bytes consisting of 48 bytes and 64 bytes of parameter save area. ABIv2 changes that to 32 bytes with no paramter save area. STACK_FRAME_OVERHEAD is in theory the minimum stack frame size, but we over 240 uses of it, some of which assume that it includes space for the parameter area. We need to work through all our stack defines and rationalise them but let's fix perf now by creating STACK_FRAME_MIN_SIZE and using in valid_next_sp(). This fixes the issue: 30.64% readseek2_proce [kernel.kallsyms] [k] find_get_entry | --- find_get_entry pagecache_get_page generic_file_read_iter new_sync_read vfs_read sys_read syscall_exit __GI___libc_read Cc: stable@vger.kernel.org # 3.16+ Reported-by: Aneesh Kumar K.V Signed-off-by: Anton Blanchard

powerpc/perf/hv-24x7: Use kmem_cache_free

2014-08-13T05:14:04Z

Free memory allocated using kmem_cache_zalloc using kmem_cache_free rather than kfree. The Coccinelle semantic patch that makes this change is as follows: // @@ expression x,E,c; @@ x = \(kmem_cache_alloc\|kmem_cache_zalloc\|kmem_cache_alloc_node\)(c,...) ... when != x = E when != &x ?-kfree(x) +kmem_cache_free(c,x) // Signed-off-by: Himangi Saraogi Acked-by: Julia Lawall Signed-off-by: Benjamin Herrenschmidt

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

2014-08-07T15:50:34Z

Pull powerpc updates from Ben Herrenschmidt: "This is the powerpc new goodies for 3.17. The short story: The biggest bit is Michael removing all of pre-POWER4 processor support from the 64-bit kernel. POWER3 and rs64. This gets rid of a ton of old cruft that has been bitrotting in a long while. It was broken for quite a few versions already and nobody noticed. Nobody uses those machines anymore. While at it, he cleaned up a bunch of old dusty cabinets, getting rid of a skeletton or two. Then, we have some base VFIO support for KVM, which allows assigning of PCI devices to KVM guests, support for large 64-bit BARs on "powernv" platforms, support for HMI (Hardware Management Interrupts) on those same platforms, some sparse-vmemmap improvements (for memory hotplug), There is the usual batch of Freescale embedded updates (summary in the merge commit) and fixes here or there, I think that's it for the highlights" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (102 commits) powerpc/eeh: Export eeh_iommu_group_to_pe() powerpc/eeh: Add missing #ifdef CONFIG_IOMMU_API powerpc: Reduce scariness of interrupt frames in stack traces powerpc: start loop at section start of start in vmemmap_populated() powerpc: implement vmemmap_free() powerpc: implement vmemmap_remove_mapping() for BOOK3S powerpc: implement vmemmap_list_free() powerpc: Fail remap_4k_pfn() if PFN doesn't fit inside PTE powerpc/book3s: Fix endianess issue for HMI handling on napping cpus. powerpc/book3s: handle HMIs for cpus in nap mode. powerpc/powernv: Invoke opal call to handle hmi. powerpc/book3s: Add basic infrastructure to handle HMI in Linux. powerpc/iommu: Fix comments with it_page_shift powerpc/powernv: Handle compound PE in config accessors powerpc/powernv: Handle compound PE for EEH powerpc/powernv: Handle compound PE powerpc/powernv: Split ioda_eeh_get_state() powerpc/powernv: Allow to freeze PE powerpc/powernv: Enable M64 aperatus for PHB3 powerpc/eeh: Aux PE data for error log ...

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

2014-08-04T23:09:53Z

Pull perf changes from Ingo Molnar: "Kernel side changes: - Consolidate the PMU interrupt-disabled code amongst architectures (Vince Weaver) - misc fixes Tooling changes (new features, user visible changes): - Add support for pagefault tracing in 'trace', please see multiple examples in the changeset messages (Stanislav Fomichev). - Add pagefault statistics in 'trace' (Stanislav Fomichev) - Add header for columns in 'top' and 'report' TUI browsers (Jiri Olsa) - Add pagefault statistics in 'trace' (Stanislav Fomichev) - Add IO mode into timechart command (Stanislav Fomichev) - Fallback to syscalls:* when raw_syscalls:* is not available in the perl and python perf scripts. (Daniel Bristot de Oliveira) - Add --repeat global option to 'perf bench' to be used in benchmarks such as the existing 'futex' one, that was modified to use it instead of a local option. (Davidlohr Bueso) - Fix fd -> pathname resolution in 'trace', be it using /proc or a vfs_getname probe point. (Arnaldo Carvalho de Melo) - Add suggestion of how to set perf_event_paranoid sysctl, to help non-root users trying tools like 'trace' to get a working environment. (Arnaldo Carvalho de Melo) - Updates from trace-cmd for traceevent plugin_kvm plus args cleanup (Steven Rostedt, Jan Kiszka) - Support S/390 in 'perf kvm stat' (Alexander Yarygin) Tooling infrastructure changes: - Allow reserving a row for header purposes in the hists browser (Arnaldo Carvalho de Melo) - Various fixes and prep work related to supporting Intel PT (Adrian Hunter) - Introduce multiple debug variables control (Jiri Olsa) - Add callchain and additional sample information for python scripts (Joseph Schuchart) - More prep work to support Intel PT: (Adrian Hunter) - Polishing 'script' BTS output - 'inject' can specify --kallsym - VDSO is per machine, not a global var - Expose data addr lookup functions previously private to 'script' - Large mmap fixes in events processing - Include standard stringify macros in power pc code (Sukadev Bhattiprolu) Tooling cleanups: - Convert open coded equivalents to asprintf() (Andy Shevchenko) - Remove needless reassignments in 'trace' (Arnaldo Carvalho de Melo) - Cache the is_exit syscall test in 'trace) (Arnaldo Carvalho de Melo) - No need to reimplement err() in 'perf bench sched-messaging', drop barf(). (Davidlohr Bueso). - Remove ev_name argument from perf_evsel__hists_browse, can be obtained from the other parameters. (Jiri Olsa) Tooling fixes: - Fix memory leak in the 'sched-messaging' perf bench test. (Davidlohr Bueso) - The -o and -n 'perf bench mem' options are mutually exclusive, emit error when both are specified. (Davidlohr Bueso) - Fix scrollbar refresh row index in the ui browser, problem exposed now that headers will be added and will be allowed to be switched on/off. (Jiri Olsa) - Handle the num array type in python properly (Sebastian Andrzej Siewior) - Fix wrong condition for allocation failure (Jiri Olsa) - Adjust callchain based on DWARF debug info on powerpc (Sukadev Bhattiprolu) - Fix a risk for doing free on uninitialized pointer in traceevent lib (Rickard Strandqvist) - Update attr test with PERF_FLAG_FD_CLOEXEC flag (Jiri Olsa) - Enable close-on-exec flag on perf file descriptor (Yann Droneaud) - Fix build on gcc 4.4.7 (Arnaldo Carvalho de Melo) - Event ordering fixes (Jiri Olsa)" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (123 commits) Revert "perf tools: Fix jump label always changing during tracing" perf tools: Fix perf usage string leftover perf: Check permission only for parent tracepoint event perf record: Store PERF_RECORD_FINISHED_ROUND only for nonempty rounds perf record: Always force PERF_RECORD_FINISHED_ROUND event perf inject: Add --kallsyms parameter perf tools: Expose 'addr' functions so they can be reused perf session: Fix accounting of ordered samples queue perf powerpc: Include util/util.h and remove stringify macros perf tools: Fix build on gcc 4.4.7 perf tools: Add thread parameter to vdso__dso_findnew() perf tools: Add dso__type() perf tools: Separate the VDSO map name from the VDSO dso name perf tools: Add vdso__new() perf machine: Fix the lifetime of the VDSO temporary file perf tools: Group VDSO global variables into a structure perf session: Add ability to skip 4GiB or more perf session: Add ability to 'skip' a non-piped event stream perf tools: Pass machine to vdso__dso_findnew() perf tools: Add dso__data_size() ...

Merge tag 'v3.16-rc7' into perf/core, to merge in the latest fixes before applying new changes

2014-07-28T08:00:33Z

Signed-off-by: Ingo Molnar

powerpc/perf: Add per-event excludes on Power8

2014-07-28T04:30:58Z

Power8 has a new register (MMCR2), which contains individual freeze bits for each counter. This is an improvement on previous chips as it means we can have multiple events on the PMU at the same time with different exclude_{user,kernel,hv} settings. Previously we had to ensure all events on the PMU had the same exclude settings. The core of the patch is fairly simple. We use the 207S feature flag to indicate that the PMU backend supports per-event excludes, if it's set we skip the generic logic that enforces the equality of excludes between events. We also use that flag to skip setting the freeze bits in MMCR0, the PMU backend is expected to have handled setting them in MMCR2. The complication arises with EBB. The FCxP bits in MMCR2 are accessible R/W to a task using EBB. Which means a task using EBB will be able to see that we are using MMCR2 for freezing, whereas the old logic which used MMCR0 is not user visible. The task can not see or affect exclude_kernel & exclude_hv, so we only need to consider exclude_user. The table below summarises the behaviour both before and after this commit is applied: exclude_user true false ------------------------------------ | User visible | N N Before | Can freeze | Y Y | Can unfreeze | N Y ------------------------------------ | User visible | Y Y After | Can freeze | Y Y | Can unfreeze | Y/N Y ------------------------------------ So firstly I assert that the simple visibility of the exclude_user setting in MMCR2 is a non-issue. The event belongs to the task, and was most likely created by the task. So the exclude_user setting is not privileged information in any way. Secondly, the behaviour in the exclude_user = false case is unchanged. This is important as it is the case that is actually useful, ie. the event is created with no exclude setting and the task uses MMCR2 to implement exclusion manually. For exclude_user = true there is no meaningful change to freezing the event. Previously the task could use MMCR2 to freeze the event, though it was already frozen with MMCR0. With the new code the task can use MMCR2 to freeze the event, though it was already frozen with MMCR2. The only real change is when exclude_user = true and the task tries to use MMCR2 to unfreeze the event. Previously this had no effect, because the event was already frozen in MMCR0. With the new code the task can unfreeze the event in MMCR2, but at some indeterminate time in the future the kernel will overwrite its setting and refreeze the event. Therefore my final assertion is that any task using exclude_user = true and also fiddling with MMCR2 was deeply confused before this change, and remains so after it. Signed-off-by: Michael Ellerman Signed-off-by: Benjamin Herrenschmidt

powerpc/perf: Pass the struct perf_events down to compute_mmcr()

2014-07-28T04:30:47Z

To support per-event exclude settings on Power8 we need access to the struct perf_events in compute_mmcr(). Signed-off-by: Michael Ellerman Signed-off-by: Benjamin Herrenschmidt

powerpc/perf: Clear all MMCR settings before calling compute_mmcr()

2014-07-28T04:11:34Z

Because we reuse cpuhw->mmcr on each call to compute_mmcr() there's a risk that we could forget to set one of the values and use whatever value was in there previously. Currently all the implementations are careful to set all the values, but it's safer to clear them all before we call compute_mmcr(). Signed-off-by: Michael Ellerman Signed-off-by: Benjamin Herrenschmidt

powerpc/perf: Fix MMCR2 handling for EBB

2014-07-23T07:16:47Z

In the recent commit b50a6c584bb4 "Clear MMCR2 when enabling PMU", I screwed up the handling of MMCR2 for tasks using EBB. We must make sure we set MMCR2 *before* ebb_switch_in(), otherwise we overwrite the value of MMCR2 that userspace may have written. That potentially breaks a task that uses EBB and manually uses MMCR2 for event freezing. Fixes: b50a6c584bb4 ("powerpc/perf: Clear MMCR2 when enabling PMU") Cc: stable@vger.kernel.org Signed-off-by: Michael Ellerman Signed-off-by: Benjamin Herrenschmidt

powerpc/perf: Never program book3s PMCs with values >= 0x80000000

2014-07-11T03:50:47Z

We are seeing a lot of PMU warnings on POWER8: Can't find PMC that caused IRQ Looking closer, the active PMC is 0 at this point and we took a PMU exception on the transition from negative to 0. Some versions of POWER8 have an issue where they edge detect and not level detect PMC overflows. A number of places program the PMC with (0x80000000 - period_left), where period_left can be negative. We can either fix all of these or just ensure that period_left is always >= 1. This patch takes the second option. Cc: Signed-off-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt