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* Documentation: update libhugetlbfs site urlSeongJae Park2016-01-141-1/+1
| | | | | | | | | The site for libhugetlbfs has moved from sourceforge to github. This commit updates the old url. Signed-off-by: SeongJae Park <sj38.park@gmail.com> Acked-by: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* Documentation: Explain pci=conf1,conf2 more verboselyBorislav Petkov2016-01-141-4/+10
| | | | | | | | | | | | | | | | People complained that setting the PCI config space access mechanism through "pci=conf1" or "pci=conf2" on the command line is not really documented. Yeah, can you blame them? Look at what we have now. So try to improve the situation a bit by explaining what those "conf1" and "conf2" things actually mean. See http://wiki.osdev.org/PCI for more info. Suggested-by: Eric Morton <Eric.Morton@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> [jc: Added the above URL to the document too] Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* DMA-API: fix confusing sentence in Documentation/DMA-API.txtMasahiro Yamada2016-01-121-1/+1
| | | | | | | | Change the phrase "handed off to the driver" to "handed off to the device" as in the paragraph below. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* Documentation: translations: update linux cross reference linkSeongJae Park2016-01-123-3/+3
| | | | | | | | | | The old link to source code cross reference does not work now. Though the link has updated by commit 1d12554f0abbc7d17dce8d1b7b25f4e27555e6d7 ("Documentation: HOWTO: update code cross reference link"), there are few obsolete links yet. This commit update them. Signed-off-by: SeongJae Park <sj38.park@gmail.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* Documentation: fix typo in CodingStyleManuel Pégourié-Gonnard2016-01-121-1/+1
| | | | | | | | Simple typo: "it" for "is". Signed-off-by: Manuel Pégourié-Gonnard <mpg@elzevir.fr> Cc: Trivial Patch Monkey <trivial@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* init, Documentation: Remove ramdisk_blocksize mentionsRobert Elliott2015-12-262-10/+0
| | | | | | | | | | | | | | | | | | The brd driver has never supported the ramdisk_blocksize kernel parameter that was in the rd driver it replaced, so remove mention of this parameter from comments and Documentation. Commit 9db5579be4bb ("rewrite rd") replaced rd with brd, keeping a brd_blocksize variable in struct brd_device but never using it. Commit a2cba2913c76 ("brd: get rid of unused members from struct brd_device") removed the unused variable. Commit f5abc8e75815 ("Documentation/blockdev/ramdisk.txt: updates") removed mentions of ramdisk_blocksize from that file. Signed-off-by: Robert Elliott <elliott@hpe.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* Documentation-getdelays: Apply a recommendation from "checkpatch.pl" in main()Markus Elfring2015-12-241-1/+2
| | | | | | | | | The script "checkpatch.pl" pointed out that assignments should usually not be performed within condition checks. Thus move the assignment for the variable "nl_sd" to a separate statement. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* Documentation: HOWTO: update versions from 3.x to 4.xSeongJae Park2015-12-241-13/+13
| | | | | | | | | | | Versions in HOWTO was updated to 4.x by commit e4144fe5d47c91c92d36cdbd5f31ed8d6e3a57ab ("docs: update HOWTO for 3.x -> 4.x versioning") but not applied to Korean translation. This commit apply the change. Signed-off-by: SeongJae Park <sj38.park@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* Documentation: remove outdated references from translationsSeongJae Park2015-12-242-2/+0
| | | | | | | | | | | | Outdated link to linux-next wiki was removed by commit ace80793d16fb076381ba0e232d42295d98dae99 ("Documentation: remove outdated references to the linux-next wiki"). However, the change was not applied to translations. This commit apply the change to translations. Signed-off-by: SeongJae Park <sj38.park@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* Doc: treewide: Fix grammar "a" to "an"Masanari Iida2015-12-102-2/+2
| | | | | | | This patch fix some grammar mistake. Signed-off-by: Masanari Iida <standby24x7@gmail.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* Documentation: cpu-hotplug: Fix sysfs mount instructionsSoren Brinkmann2015-12-101-1/+1
| | | | | | | | | The instructions for mounting sysfs are inconsistent in instructing to create the directory '/sysfs' but then mounting sysfs to /sys. Also, indentation is slightly off. Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* can-doc: Add hint about getting timestampsStefan Tatschner2015-12-101-0/+9
| | | | | | | | | | This patch adds a hint about how to get timestamps of received CAN frames with ioctl(2). This hint has been applied to the former SocketCAN Documentation, but it got lost during mainlining the first bits and pieces to linux kernel. Signed-off-by: Stefan Tatschner <rumpelsepp@sevenbyte.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* Fix CFQ I/O scheduler parameter name in documentationLibor Pechacek2015-12-101-8/+7
| | | | | | | As seen in block/cfq-iosched.c, the parameter name is low_latency. Signed-off-by: Libor Pechacek <lpechacek@suse.cz> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* Documentation: arm: remove dead links from Marvell Berlin docsTom Hebb2015-12-101-3/+0
| | | | | | | | The BG2 and BG2Q are no longer listed on Marvell's site, so the links in the README go nowhere. The BG2Q's product brief has also been removed. Signed-off-by: Thomas Hebb <tommyhebb@gmail.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* Documentation: HOWTO: update code cross reference linkDoug Smythies2015-12-101-1/+1
| | | | | | | | The source code cross reference link does not work. Update the link to a site that works. Signed-off-by: Doug Smythies <dsmythies@telus.net> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* Doc: Docbook/iio: Fix typo in iio.tmplMasanari Iida2015-11-211-1/+1
| | | | | | | | This patch fix a spelling typo in iio.tmpl. Signed-off-by: Masanari Iida <standby24x7@gmail.com> Acked-by: Daniel Baluta <daniel.baluta@intel.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* DocBook: make index.html generation less verbose by defaultMauro Carvalho Chehab2015-11-211-2/+3
| | | | | | | | | | | | | | | | When make htmldocs is called on non-verbose mode, it will still be verbose with index.html generation for no good reason, printing: rm -rf Documentation/DocBook/index.html; echo '<h1>Linux Kernel HTML Documentation</h1>' >> Documentation/DocBook/index.html && echo '<h2>Kernel Version: 4.4.0-rc1</h2>' >> Documentation/DocBook/index.html && cat Documentation/DocBook/iio.html >> Documentation/DocBook/index.html Instead, use the standard non-verbose mode, using: HTML Documentation/DocBook/index.html if not called with V=1. Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* DocBook: Cleanup: remove an unused $(call) lineMauro Carvalho Chehab2015-11-211-1/+0
| | | | | | | | | There's no build_images function to call. So remove it. This is just a cleanup patch, with doesn't affect the build. Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* DocBook: Add a help message for DOCBOOKS env varMauro Carvalho Chehab2015-11-211-0/+4
| | | | | | | | | Sometimes, it is needed to compile only a subset of the possible DocBooks. This is supported by the building system, but it is not docummented. Add a documentation for it. Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* stable_kernel_rules.txt: Remove extra space after Cc:Richard Weinberger2015-11-211-1/+1
| | | | | | | | | | | | Fixes the checkpatch.pl warning: "WARNING: Use a single space after Cc:" Very lazy hackers just copy&paste the stable tag from this document. As it contains an extra space, checkpatch.pl will not like the resulting patch... Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* Doc: ioctl: Fix typos in Documentation/ioctlMasanari Iida2015-11-211-3/+3
| | | | | | | | This patch fix some spelling typos in Documentation/ioctl. Signed-off-by: Masanari Iida <standby24x7@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* Doc: gpio: Fix typos in Documentation/gpioMasanari Iida2015-11-213-7/+7
| | | | | | | | This patch fix some spelling typos found in Documentation/gpio. Signed-off-by: Masanari Iida <standby24x7@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* Documentation: arm: remove hyphen from BG2Q in Marvell Berlin docsTom Hebb2015-11-211-1/+1
| | | | | | | | | The chip's design name isn't hyphenated anywhere else, and none of the other names in the same document are hyphenated. Signed-off-by: Thomas Hebb <tommyhebb@gmail.com> Acked-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* Documentation: arm: add Marvell Armada 1500 Mini Plus to SoC listTom Hebb2015-11-211-1/+5
| | | | | | | | | Add known information about the Marvell BG2CDP SoC that's used in the Google Chromecast 2015 and Kinoma HD devices. Signed-off-by: Thomas Hebb <tommyhebb@gmail.com> Acked-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* Documentation: arm: update homepage URLs for Marvell Berlin SoCsTom Hebb2015-11-211-7/+7
| | | | | | | | | | Marvell has renamed their Berlin family from "Digital Entertainment" to "Multimedia Solutions." There aren't proper redirects set up for device-specific pages, so update the URLs accordingly. Signed-off-by: Thomas Hebb <tommyhebb@gmail.com> Acked-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* kernel-doc: Fix parsing of DECLARE_BITMAP in structConchúr Navid2015-11-211-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | Some documented structures in the kernel use DECLARE_BITMAP to create arrays of unsigned longs to store information using the bitmap functions. These have to be replaced with a parsable version for kernel-doc. For example a simple input like /** * struct something - some test * @members: active members */ struct something { DECLARE_BITMAP(members, MAX_MEMBERS); }; resulted in parsing warnings like warning: No description found for parameter 'MAX_MEMBERS)' warning: Excess struct/union/enum/typedef member 'members' description in 'something' Signed-off-by: Conchúr Navid <conchur@web.de> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* kernel-doc: Strip #ifdef/#endif in enumsConchúr Navid2015-11-211-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Some enumerations in the kernel headers use #ifdef to reduce their size based on the the configuration. These lines have to be stripped to avoid parsing problems. For example a simple input like /** * enum flags - test flags * @flag1: first flag * @flag2: second flag */ enum flags { flag1 = BIT(0), #ifdef SECOND_FLAG flag2 = BIT(1), #endif }; resulted in parsing warnings like warning: Enum value '#ifdef SECOND_FLAG;flag2 = BIT(1)' not described in enum 'flags' warning: Enum value '#endif;' not described in enum 'flags' Signed-off-by: Conchúr Navid <conchur@web.de> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* kernel-doc: Fix stripping of #define in enumsConchúr Navid2015-11-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The regex to strip single line #define's in enumerations depends on the fact that the defines are still stored on separate lines. But the surrounding code already removed newlines and replaced them with semicolons. For example a simple input like /** * enum flags - test flags * @flag1: first flag * @flag2: second flag * @flag3: third flag * @flag4: fourth flag */ enum flags { flag1 = BIT(0), flag2 = BIT(1), #define flags_small (flag1 | flag2) flag3 = BIT(2), flag4 = BIT(3), #define flags_big (flag2 | flag3) }; resulted in parsing warnings like warning: Enum value '#define flags_small (flag1 | flag2);flag3 = BIT(2)' not described in enum 'flags' warning: Enum value '#define flags_big (flag2 | flag3);' not described in enum 'flags' Signed-off-by: Conchúr Navid <conchur@web.de> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* Linux 4.4-rc1v4.4-rc1Linus Torvalds2015-11-161-2/+2
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* Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds2015-11-1537-292/+947
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf updates from Thomas Gleixner: "Mostly updates to the perf tool plus two fixes to the kernel core code: - Handle tracepoint filters correctly for inherited events (Peter Zijlstra) - Prevent a deadlock in perf_lock_task_context (Paul McKenney) - Add missing newlines to some pr_err() calls (Arnaldo Carvalho de Melo) - Print full source file paths when using 'perf annotate --print-line --full-paths' (Michael Petlan) - Fix 'perf probe -d' when just one out of uprobes and kprobes is enabled (Wang Nan) - Add compiler.h to list.h to fix 'make perf-tar-src-pkg' generated tarballs, i.e. out of tree building (Arnaldo Carvalho de Melo) - Add the llvm-src-base.c and llvm-src-kbuild.c files, generated by the 'perf test' LLVM entries, when running it in-tree, to .gitignore (Yunlong Song) - libbpf error reporting improvements, using a strerror interface to more precisely tell the user about problems with the provided scriptlet, be it in C or as a ready made object file (Wang Nan) - Do not be case sensitive when searching for matching 'perf test' entries (Arnaldo Carvalho de Melo) - Inform the user about objdump failures in 'perf annotate' (Andi Kleen) - Improve the LLVM 'perf test' entry, introduce a new ones for BPF and kbuild tests to check the environment used by clang to compile .c scriptlets (Wang Nan)" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits) perf/x86/intel/rapl: Remove the unused RAPL_EVENT_DESC() macro tools include: Add compiler.h to list.h perf probe: Verify parameters in two functions perf session: Add missing newlines to some pr_err() calls perf annotate: Support full source file paths for srcline fix perf test: Add llvm-src-base.c and llvm-src-kbuild.c to .gitignore perf: Fix inherited events vs. tracepoint filters perf: Disable IRQs across RCU RS CS that acquires scheduler lock perf test: Do not be case sensitive when searching for matching tests perf test: Add 'perf test BPF' perf test: Enhance the LLVM tests: add kbuild test perf test: Enhance the LLVM test: update basic BPF test program perf bpf: Improve BPF related error messages perf tools: Make fetch_kernel_version() publicly available bpf tools: Add new API bpf_object__get_kversion() bpf tools: Improve libbpf error reporting perf probe: Cleanup find_perf_probe_point_from_map to reduce redundancy perf annotate: Inform the user about objdump failures in --stdio perf stat: Make stat options global perf sched latency: Fix thread pid reuse issue ...
| * perf/x86/intel/rapl: Remove the unused RAPL_EVENT_DESC() macroHuang Rui2015-11-121-6/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Huang Rui <ray.huang@amd.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Borislav Petkov <bp@suse.de> Cc: Dasaratharaman Chandramouli <dasaratharaman.chandramouli@intel.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Li <tony.li@amd.com> Link: http://lkml.kernel.org/r/1446630233-3166-1-git-send-email-ray.huang@amd.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * Merge tag 'perf-urgent-for-mingo' of ↵Ingo Molnar2015-11-125-4/+14
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent Pull perf/urgent fixes from Arnaldo Carvalho de Melo: - Add missing newlines to some pr_err() calls (Arnaldo Carvalho de Melo) - Print full source file paths when using 'perf annotate --print-line --full-paths' (Michael Petlan) - Fix 'perf probe -d' when just one out of uprobes and kprobes is enabled (Wang Nan) - Add compiler.h to list.h to fix 'make perf-tar-src-pkg' generated tarballs, i.e. out of tree building (Arnaldo Carvalho de Melo) - Add the llvm-src-base.c and llvm-src-kbuild.c files, generated by the 'perf test' LLVM entries, when running it in-tree, to .gitignore (Yunlong Song) Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * tools include: Add compiler.h to list.hArnaldo Carvalho de Melo2015-11-111-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | list.h needs WRITE_ONCE() since 7f5f873c6a07 ("rculist: Use WRITE_ONCE() when deleting from reader-visible list") add it before including the kernel's list.h file. This fixes builds of 'make perf-tar-src-pkg' perf tool tarball builds, i.e. out of tree builds. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-e0rb8f7jwz0jn24ttyick9u6@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * perf probe: Verify parameters in two functionsWang Nan2015-11-111-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On kernel with only one out of CONFIG_KPROBE_EVENTS and CONFIG_UPROBE_EVENTS enabled, 'perf probe -d' causes a segfault because perf_del_probe_events() calls probe_file__get_events() with a negative fd. This patch fixes it by adding parameter validation at the entry of probe_file__get_events() and probe_file__get_rawlist(). Since they are both non-static public functions (in .h file), parameter verifying is required. v1 -> v2: Verify fd at the head of probe_file__get_rawlist() instead of checking at call site (suggested by Masami and Arnaldo at [1,2]). [1] http://lkml.kernel.org/r/50399556C9727B4D88A595C8584AAB37526048E3@GSjpTKYDCembx32.service.hitachi.net [2] http://lkml.kernel.org/r/20151105155830.GV13236@kernel.org Signed-off-by: Wang Nan <wangnan0@huawei.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1446803415-83382-1-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * perf session: Add missing newlines to some pr_err() callsArnaldo Carvalho de Melo2015-11-111-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Before: [acme@zoo linux]$ perf evlist WARNING: The perf.data file's data size field is 0 which is unexpected. Was the 'perf record' command properly terminated? non matching sample_type[acme@zoo linux]$ After: [acme@zoo linux]$ perf evlist WARNING: The perf.data file's data size field is 0 which is unexpected. Was the 'perf record' command properly terminated? non matching sample_type [acme@zoo linux]$ Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-wscok3a2s7yrj8156oc2r6qe@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * perf annotate: Support full source file paths for srcline fixMichael Petlan2015-11-111-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The --full-paths option did not show the full source file paths in the 'perf annotate' tool, because the value of the option was not propagated into the related functions. With this patch the value of the --full-paths option is known to the function that composes the srcline string, so it prints the full path when necessary. Committer Note: This affects annotate when the --print-line option is used: # perf annotate -h 2>&1 | grep print-line -l, --print-line print matching source lines (may be slow) Looking just at the lines that should be affected by this change: Before: # perf annotate --print-line --full-paths --stdio fput | grep '\.[ch]:[0-9]\+' 94.44 atomic64_64.h:114 5.56 file_table.c:265 file_table.c:265 5.56 : ffffffff81219a00: callq ffffffff81769360 <__fentry__> atomic64_64.h:114 94.44 : ffffffff81219a05: lock decq 0x38(%rdi) After: # perf annotate --print-line --full-paths --stdio fput | grep '\.[ch]:[0-9]\+' 94.44 /home/git/linux/arch/x86/include/asm/atomic64_64.h:114 5.56 /home/git/linux/fs/file_table.c:265 /home/git/linux/fs/file_table.c:265 5.56 : ffffffff81219a00: callq ffffffff81769360 <__fentry__> /home/git/linux/arch/x86/include/asm/atomic64_64.h:114 94.44 : ffffffff81219a05: lock decq 0x38(%rdi) # Signed-off-by: Michael Petlan <mpetlan@redhat.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Link: http://permalink.gmane.org/gmane.linux.kernel.perf.user/2365 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * perf test: Add llvm-src-base.c and llvm-src-kbuild.c to .gitignoreYunlong Song2015-11-111-0/+2
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit b31de018a6284a25e0fdfeb028e724f8417ec3b1 ("perf test: Enhance the LLVM test: update basic BPF test program") dynamically creates file llvm-src-base.c during the perf building. Similarly, the commit 7af3f3d55b80cce40ad94b6b8e173dccedaf25e6 ("perf test: Enhance the LLVM tests: add kbuild test") dynamically creates file llvm-src-kbuild.c during the perf building. Add them to .gitignore. Signed-off-by: Yunlong Song <yunlong.song@huawei.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Kan Liang <kan.liang@intel.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Fixes: b31de018a628 ("perf test: Enhance the LLVM test: update basic BPF test program") Fixes: 7af3f3d55b80 ("perf test: Enhance the LLVM tests: add kbuild test") Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * perf: Fix inherited events vs. tracepoint filtersPeter Zijlstra2015-11-091-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Arnaldo reported that tracepoint filters seem to misbehave (ie. not apply) on inherited events. The fix is obvious; filters are only set on the actual (parent) event, use the normal pattern of using this parent event for filters. This is safe because each child event has a reference to it. Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frédéric Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wang Nan <wangnan0@huawei.com> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20151102095051.GN17308@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * perf: Disable IRQs across RCU RS CS that acquires scheduler lockPaul E. McKenney2015-11-091-8/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The perf_lock_task_context() function disables preemption across its RCU read-side critical section because that critical section acquires a scheduler lock. If there was a preemption during that RCU read-side critical section, the rcu_read_unlock() could attempt to acquire scheduler locks, resulting in deadlock. However, recent optimizations to expedited grace periods mean that IPI handlers that execute during preemptible RCU read-side critical sections can now cause the subsequent rcu_read_unlock() to acquire scheduler locks. Disabling preemption does nothiing to prevent these IPI handlers from executing, so these optimizations introduced a deadlock. In theory, this deadlock could be avoided by pulling all wakeups and printk()s out from rnp->lock critical sections, but in practice this would re-introduce some RCU CPU stall warning bugs. Given that acquiring scheduler locks entails disabling interrupts, these deadlocks can be avoided by disabling interrupts (instead of disabling preemption) across any RCU read-side critical that acquires scheduler locks and holds them across the rcu_read_unlock(). This commit therefore makes this change for perf_lock_task_context(). Reported-by: Dave Jones <davej@codemonkey.org.uk> Reported-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Stephane Eranian <eranian@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20151104134838.GR29027@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * Merge tag 'perf-core-for-mingo-2' of ↵Ingo Molnar2015-11-0831-274/+920
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo: Fixes: - libbpf error reporting improvements, using a strerror interface to more precisely tell the user about problems with the provided scriptlet, be it in C or as a ready made object file (Wang Nan) - Do not be case sensitive when searching for matching 'perf test' entries (Arnaldo Carvalho de Melo) - Inform the user about objdump failures in 'perf annotate' (Andi Kleen) Infrastructure changes: - Improve the LLVM 'perf test' entry, introduce a new ones for BPF and kbuild tests to check the environment used by clang to compile .c scriptlets (Wang Nan) Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * perf test: Do not be case sensitive when searching for matching testsArnaldo Carvalho de Melo2015-11-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Before: # perf test llvm # perf test LLVM 35: Test LLVM searching and compiling : Ok # After # perf test llvm 35: Test LLVM searching and compiling : Ok # Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-c1u05npqbf6epse17ovfejoj@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * perf test: Add 'perf test BPF'Wang Nan2015-11-066-1/+248
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds BPF testcase for testing BPF event filtering. By utilizing the result of 'perf test LLVM', this patch compiles the eBPF sample program then test its ability. The BPF script in 'perf test LLVM' lets only 50% samples generated by epoll_pwait() to be captured. This patch runs that system call for 111 times, so the result should contain 56 samples. Signed-off-by: Wang Nan <wangnan0@huawei.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1446817783-86722-8-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * perf test: Enhance the LLVM tests: add kbuild testWang Nan2015-11-064-1/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds a kbuild testcase to check whether kernel headers can be correctly found. For example: # mv /lib/modules/4.3.0-rc5{,.bak} # perf test LLVM 38: Test LLVM searching and compiling : Skip # perf test -v LLVM ... <stdin>:11:10: fatal error: 'uapi/linux/fs.h' file not found #include <uapi/linux/fs.h> ^ 1 error generated. ERROR: unable to compile - Hint: Check error message shown above. Hint: You can also pre-compile it into .o using: clang -target bpf -O2 -c - with proper -I and -D options. Failed to compile test case: 'Test kbuild searching' test child finished with -2 Signed-off-by: Wang Nan <wangnan0@huawei.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1446817783-86722-7-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * perf test: Enhance the LLVM test: update basic BPF test programWang Nan2015-11-064-31/+129
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch replaces the original toy BPF program with the previously introduced bpf-script-example.c. Dynamically embeddeding it into 'llvm-src-base.c'. The newly introduced BPF program attaches a BPF program to 'sys_epoll_pwait()'. perf itself never use that syscall, so further test can verify their result with it. The program would generate 1 sample in every 2 calls of epoll_pwait() system call. Since the resulting BPF object is useful per se for further tests, test_llvm__fetch_bpf_obj() is introduced for creating BPF objects from source. The LLVM test was rewritten to use it. Committer note: Running it: [root@zoo wb]# perf test -v LLVM 35: Test LLVM searching and compiling : --- start --- test child forked, pid 17740 Kernel build dir is set to /lib/modules/4.3.0-rc1+/build set env: KBUILD_DIR=/lib/modules/4.3.0-rc1+/build unset env: KBUILD_OPTS include option is set to -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/4.9.2/include -I/home/git/linux/arch/x86/include -Iarch/x86/include/generated/uapi -Iarch/x86/include/generated -I/home/git/linux/include -Iinclude -I/home/git/linux/arch/x86/include/uapi -Iarch/x86/include/generated/uapi -I/home/git/linux/include/uapi -Iinclude/generated/uapi -include /home/git/linux/include/linux/kconfig.h set env: NR_CPUS=4 set env: LINUX_VERSION_CODE=0x40300 set env: CLANG_EXEC=/usr/libexec/icecc/bin/clang set env: CLANG_OPTIONS=-xc set env: KERNEL_INC_OPTIONS= -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/4.9.2/include -I/home/git/linux/arch/x86/include -Iarch/x86/include/generated/uapi -Iarch/x86/include/generated -I/home/git/linux/include -Iinclude -I/home/git/linux/arch/x86/include/uapi -Iarch/x86/include/generated/uapi -I/home/git/linux/include/uapi -Iinclude/generated/uapi -include /home/git/linux/include/linux/kconfig.h set env: WORKING_DIR=/lib/modules/4.3.0-rc1+/build set env: CLANG_SOURCE=- llvm compiling command template: echo '/* * bpf-script-example.c * Test basic LLVM building */ #ifndef LINUX_VERSION_CODE # error Need LINUX_VERSION_CODE # error Example: for 4.2 kernel, put 'clang-opt="-DLINUX_VERSION_CODE=0x40200" into llvm section of ~/.perfconfig' #endif #define BPF_ANY 0 #define BPF_MAP_TYPE_ARRAY 2 #define BPF_FUNC_map_lookup_elem 1 #define BPF_FUNC_map_update_elem 2 static void *(*bpf_map_lookup_elem)(void *map, void *key) = (void *) BPF_FUNC_map_lookup_elem; static void *(*bpf_map_update_elem)(void *map, void *key, void *value, int flags) = (void *) BPF_FUNC_map_update_elem; struct bpf_map_def { unsigned int type; unsigned int key_size; unsigned int value_size; unsigned int max_entries; }; #define SEC(NAME) __attribute__((section(NAME), used)) struct bpf_map_def SEC("maps") flip_table = { .type = BPF_MAP_TYPE_ARRAY, .key_size = sizeof(int), .value_size = sizeof(int), .max_entries = 1, }; SEC("func=sys_epoll_pwait") int bpf_func__sys_epoll_pwait(void *ctx) { int ind =0; int *flag = bpf_map_lookup_elem(&flip_table, &ind); int new_flag; if (!flag) return 0; /* flip flag and store back */ new_flag = !*flag; bpf_map_update_elem(&flip_table, &ind, &new_flag, BPF_ANY); return new_flag; } char _license[] SEC("license") = "GPL"; int _version SEC("version") = LINUX_VERSION_CODE; ' | $CLANG_EXEC -D__KERNEL__ -D__NR_CPUS__=$NR_CPUS -DLINUX_VERSION_CODE=$LINUX_VERSION_CODE $CLANG_OPTIONS $KERNEL_INC_OPTIONS -Wno-unused-value -Wno-pointer-sign -working-directory $WORKING_DIR -c "$CLANG_SOURCE" -target bpf -O2 -o - test child finished with 0 ---- end ---- Test LLVM searching and compiling: Ok [root@zoo wb]# Signed-off-by: Wang Nan <wangnan0@huawei.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1446817783-86722-6-git-send-email-wangnan0@huawei.com Signed-off-by: He Kuang <hekuang@huawei.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * perf bpf: Improve BPF related error messagesWang Nan2015-11-064-15/+108
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A series of bpf loader related error codes were introduced to help error reporting. Functions were improved to return these new error codes. Functions which return pointers were adjusted to encode error codes into return value using the ERR_PTR() interface. bpf_loader_strerror() was improved to convert these error messages to strings. It checks the error codes and calls libbpf_strerror() and strerror_r() accordingly, so caller don't need to consider checking the range of the error code. In bpf__strerror_load(), print kernel version of running kernel and the object's 'version' section to notify user how to fix his/her program. v1 -> v2: Use macro for error code. Fetch error message based on array index, eliminate for-loop. Print version strings. Before: # perf record -e ./test_kversion_nomatch_program.o sleep 1 event syntax error: './test_kversion_nomatch_program.o' \___ Failed to load program: Validate your program and check 'license'/'version' sections in your object SKIP After: # perf record -e ./test_kversion_nomatch_program.o ls event syntax error: './test_kversion_nomatch_program.o' \___ 'version' (4.4.0) doesn't match running kernel (4.3.0) SKIP Signed-off-by: Wang Nan <wangnan0@huawei.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1446818289-87444-1-git-send-email-wangnan0@huawei.com [ Add 'static inline' to bpf__strerror_prepare_load() when LIBBPF is disabled ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * perf tools: Make fetch_kernel_version() publicly availableWang Nan2015-11-063-33/+49
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are 2 places in llvm-utils.c which find kernel version information through uname. This patch extracts the uname related code into a fetch_kernel_version() function and puts it into util.h so it can be reused. Signed-off-by: Wang Nan <wangnan0@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1446818135-87310-1-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * bpf tools: Add new API bpf_object__get_kversion()Wang Nan2015-11-062-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | bpf_object__get_kversion() can be used to fetch value of object's 'version' section. Following patch will use it for error reporting. Signed-off-by: Wang Nan <wangnan0@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1446817783-86722-3-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * bpf tools: Improve libbpf error reportingWang Nan2015-11-065-59/+159
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In this patch, a series of libbpf specific error numbers and libbpf_strerror() are introduced to help reporting errors. Functions are updated to pass correct the error number through the CHECK_ERR() macro. All users of bpf_object__open{_buffer}() and bpf_program__title() in perf are modified accordingly. In addition, due to the error codes changing, bpf__strerror_load() is also modified to use them. bpf__strerror_head() is also changed accordingly so it can parse libbpf errors. bpf_loader_strerror() is introduced for that purpose, and will be improved by the following patch. load_program() is improved not to dump log buffer if it is empty. log buffer is also used to deduce whether the error was caused by an invalid program or other problem. v1 -> v2: - Using macro for error code. - Fetch error message based on array index, eliminate for-loop. - Use log buffer to detect the reason of failure. 3 new error code are introduced to replace LIBBPF_ERRNO__LOAD. In v1: # perf record -e ./test_ill_program.o ls event syntax error: './test_ill_program.o' \___ Failed to load program: Validate your program and check 'license'/'version' sections in your object SKIP # perf record -e ./test_kversion_nomatch_program.o ls event syntax error: './test_kversion_nomatch_program.o' \___ Failed to load program: Validate your program and check 'license'/'version' sections in your object SKIP # perf record -e ./test_big_program.o ls event syntax error: './test_big_program.o' \___ Failed to load program: Validate your program and check 'license'/'version' sections in your object SKIP In v2: # perf record -e ./test_ill_program.o ls event syntax error: './test_ill_program.o' \___ Kernel verifier blocks program loading SKIP # perf record -e ./test_kversion_nomatch_program.o event syntax error: './test_kversion_nomatch_program.o' \___ Incorrect kernel version SKIP (Will be further improved by following patches) # perf record -e ./test_big_program.o event syntax error: './test_big_program.o' \___ Program too big SKIP Signed-off-by: Wang Nan <wangnan0@huawei.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1446817783-86722-2-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * perf probe: Cleanup find_perf_probe_point_from_map to reduce redundancyMasami Hiramatsu2015-11-061-5/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In find_perf_probe_point_from_map(), the 'ret' variable is initialized with -ENOENT but overwritten by the return code of kernel_get_symbol_address_by_name(), and after that it is re-initialized with -ENOENT again. Setting ret=-ENOENT twice looks a bit redundant. This avoids the overwriting and just returns -ENOENT if some error happens to simplify the code. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Cc: Zefan Li <lizefan@huawei.com> Link: http://lkml.kernel.org/n/tip-ufp1zgbktzmttcputozneomd@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * perf annotate: Inform the user about objdump failures in --stdioAndi Kleen2015-11-061-2/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the browser fails to annotate it is difficult for users to find out what went wrong. Add some errors for objdump failures that are displayed in the UI. Note it would be even better to handle these errors smarter, like falling back to the binary when the debug info is somehow corrupted. But for now just giving a better error is an improvement. Committer note: This works for --stdio, where errors just scroll by the screen: # perf annotate --stdio intel_idle Failure running objdump --start-address=0xffffffff81418290 --stop-address=0xffffffff814183ae -l -d --no-show-raw -S -C /root/.debug/.build-id/28/2777c262e6b3c0451375163c9a81c893218ab1 2>/dev/null|grep -v /root/.debug/.build-id/28/2777c262e6b3c0451375163c9a81c893218ab1|expand Percent | Source code & Disassembly of vmlinux for cycles:pp ------------------------------------------------------------------ And with that one can use that command line to try to find out more about what happened instead of getting a blank screen, an improvement. We need tho to improve this further to get it to work with other UIs, like --tui and --gtk, where it continues showing a blank screen, no messages, as the pr_err() used is enough just for --stdio. Signed-off-by: Andi Kleen <ak@linux.intel.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lkml.kernel.org/r/1446779167-18949-1-git-send-email-andi@firstfloor.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>