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| | * | | | jump label: Introduce static_branch() interfaceJason Baron2011-04-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce: static __always_inline bool static_branch(struct jump_label_key *key); instead of the old JUMP_LABEL(key, label) macro. In this way, jump labels become really easy to use: Define: struct jump_label_key jump_key; Can be used as: if (static_branch(&jump_key)) do unlikely code enable/disale via: jump_label_inc(&jump_key); jump_label_dec(&jump_key); that's it! For the jump labels disabled case, the static_branch() becomes an atomic_read(), and jump_label_inc()/dec() are simply atomic_inc(), atomic_dec() operations. We show testing results for this change below. Thanks to H. Peter Anvin for suggesting the 'static_branch()' construct. Since we now require a 'struct jump_label_key *key', we can store a pointer into the jump table addresses. In this way, we can enable/disable jump labels, in basically constant time. This change allows us to completely remove the previous hashtable scheme. Thanks to Peter Zijlstra for this re-write. Testing: I ran a series of 'tbench 20' runs 5 times (with reboots) for 3 configurations, where tracepoints were disabled. jump label configured in avg: 815.6 jump label *not* configured in (using atomic reads) avg: 800.1 jump label *not* configured in (regular reads) avg: 803.4 Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20110316212947.GA8792@redhat.com> Signed-off-by: Jason Baron <jbaron@redhat.com> Suggested-by: H. Peter Anvin <hpa@linux.intel.com> Tested-by: David Daney <ddaney@caviumnetworks.com> Acked-by: Ralf Baechle <ralf@linux-mips.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| | * | | | tracing: Avoid soft lockup in trace_pipeJiri Olsa2011-04-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | running following commands: # enable the binary option echo 1 > ./options/bin # disable context info option echo 0 > ./options/context-info # tracing only events echo 1 > ./events/enable cat trace_pipe plus forcing system to generate many tracing events, is causing lockup (in NON preemptive kernels) inside tracing_read_pipe function. The issue is also easily reproduced by running ltp stress test. (ftrace_stress_test.sh) The reasons are: - bin/hex/raw output functions for events are set to trace_nop_print function, which prints nothing and returns TRACE_TYPE_HANDLED value - LOST EVENT trace do not handle trace_seq overflow These reasons force the while loop in tracing_read_pipe function never to break. The attached patch fixies handling of lost event trace, and changes trace_nop_print to print minimal info, which is needed for the correct tracing_read_pipe processing. v2 changes: - omit the cond_resched changes by trace_nop_print changes - WARN changed to WARN_ONCE and added info to be able to find out the culprit v3 changes: - make more accurate patch comment Signed-off-by: Jiri Olsa <jolsa@redhat.com> LKML-Reference: <20110325110518.GC1922@jolsa.brq.redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| | * | | | tracing: Print trace_bprintk() formats for modules tooSteven Rostedt2011-04-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The file debugfs/tracing/printk_formats maps the addresses to the formats that are used by trace_bprintk() so that userspace tools can read the buffer and be able to decode trace_bprintk events to get the format saved when reading the ring buffer directly. This is because trace_bprintk() does not store the format into the buffer, but just the address of the format, which is hidden in the kernel memory. But currently it only exports trace_bprintk()s from the kernel core and not for modules. The modules need their formats exported as well. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| | * | | | tracing: Convert trace_printk() formats for module to const char *Steven Rostedt2011-04-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The trace_printk() formats for modules do not show up in the debugfs/tracing/printk_formats file. Only the formats that are for trace_printk()s that are in the kernel core. To facilitate the change to add trace_printk() formats from modules into that file as well, we need to convert the structure that holds the formats from char fmt[], into const char *fmt, and allocate them separately. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | | | perf events, x86, P4: Fix typo in commentJustin P. Mattock2011-04-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Justin P. Mattock <justinmattock@gmail.com> Acked-by: Cyrill Gorcunov <gorcunov@gmail.com> Cc: trivial@kernel.org Link: http://lkml.kernel.org/r/1303492132-3004-1-git-send-email-justinmattock@gmail.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | perf, x86: P4 PMU -- Use perf_sample_data_init helperCyrill Gorcunov2011-04-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of opencoded assignments better to use perf_sample_data_init helper. Tested-by: Lin Ming <ming.m.lin@intel.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Signed-off-by: Don Zickus <dzickus@redhat.com> Cc: Cyrill Gorcunov <gorcunov@gmail.com> Link: http://lkml.kernel.org/r/1303398203-2918-2-git-send-email-dzickus@redhat.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | Merge branch 'linus' into perf/coreIngo Molnar2011-04-22
| |\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge reason: Pick up upstream fixes. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | perf script: improve validation of sample attributes for output fieldsDavid Ahern2011-04-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Check for required sample attributes using evsel rather than sample_type in the session header. If the attribute for a default field is not present for the event type (e.g., new command operating on file from older kernel) the field is removed from the output list. Expected event types must exist. For example, if a user specifies -f trace:time,trace -f sw:time,cpu,sym the perf.data file must contain both tracepoints and software events (ie., it is an error if either does not exist in the file). Attribute checking is done once at the beginning of perf-script rather than for each sample. v1 -> v2: - addressed comments from acme Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1302148460-570-1-git-send-email-daahern@cisco.com Signed-off-by: David Ahern <daahern@cisco.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * | | | | | perf script: Add support for PERF_TYPE_RAWArun Sharma2011-04-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Useful for getting stack traces for hardware events not handled by PERF_TYPE_HARDWARE. Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tom Zanussi <tzanussi@gmail.com> Signed-off-by: Arun Sharma <asharma@fb.com> Link: http://lkml.kernel.org/n/tip-qimdcdpekjqxuyqovy4kjusx@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * | | | | | perf tools: git mv tools/perf/{features-tests.mak,config/}Michael Witten2011-04-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Michael Witten <mfwitten@gmail.com> Link: http://lkml.kernel.org/n/tip-a6zhefjayuounko1tk5sjji2@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * | | | | | perf tools: Move `try-cc'Michael Witten2011-04-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The `try-cc' user-defined function was in tools/perf/feature-tests.mak; this commit moves it to tools/perf/config/utilities.mak. Signed-off-by: Michael Witten <mfwitten@gmail.com> Link: http://lkml.kernel.org/n/tip-bqhwcuxsrve0iodn6q4ejaoi@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * | | | | | perf tools: Makefile: PYTHON{,_CONFIG} to bandage Python 3 incompatibilityMichael Witten2011-04-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, Python 3 is not supported by perf's code; this can cause the build to fail for systems that have Python 3 installed as the default python: python{,-config} The Correct Solution is to write compatibility code so that Python 3 works out-of-the-box. However, users often have an ancillary Python 2 installed: python2{,-config} Therefore, a quick fix is to allow the user to specify those ancillary paths as the python binaries that Makefile should use, thereby avoiding Python 3 altogether; as an added benefit, the Python binaries may be installed in non-standard locations without the need for updating any PATH variable. This commit adds the ability to set PYTHON and/or PYTHON_CONFIG either as environment variables or as make variables on the command line; the paths may be relative, and usually only PYTHON is necessary in order for PYTHON_CONFIG to be defined implicitly. Some rudimentary error checking is performed when the user explicitly specifies a value for any of these variables. In addition, this commit introduces significantly robust makefile infrastructure for working with paths and communicating with the shell; it's currently only used for handling Python, but I hope it will prove useful in refactoring the makefiles. Thanks to: Raghavendra D Prabhu <rprabhu@wnohang.net> for motivating this patch. Acked-by: Raghavendra D Prabhu <rprabhu@wnohang.net> Link: http://lkml.kernel.org/r/e987828e-87ec-4973-95e7-47f10f5d9bab-mfwitten@gmail.com Signed-off-by: Michael Witten <mfwitten@gmail.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * | | | | | perf tools: Makefile: Clean up `python/perf.so' ruleMichael Witten2011-04-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is no need for a subshell or an explicit `export'; as per the POSIX Shell Command Language specification: http://pubs.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_09_01 http://pubs.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_10_02 It is only necessary to include the environment variable assignment just before the command to be run. Also, it is better to use single-quotes, because GNU make might expand `$(BASIC_CFLAGS)' into something that the shell could interpret within double-quotes. Acked-by: Raghavendra D Prabhu <rprabhu@wnohang.net> Link: http://lkml.kernel.org/n/tip-58n38o02ocuzrm9qh096hsf5@git.kernel.org Signed-off-by: Michael Witten <mfwitten@gmail.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * | | | | | perf symbols: Give more useful names to 'self' parametersArnaldo Carvalho de Melo2011-04-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | One more installment on an area that is mostly dormant. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tom Zanussi <tzanussi@gmail.com> LKML-Reference: <new-submission> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * | | | | | perf, x86: Use ALTERNATIVE() to check for X86_FEATURE_PERFCTR_CORERobert Richter2011-04-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Using ALTERNATIVE() when checking for X86_FEATURE_PERFCTR_CORE avoids an extra pointer chase and data cache hit. Signed-off-by: Robert Richter <robert.richter@amd.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1302913676-14352-4-git-send-email-robert.richter@amd.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | Merge branch 'perf/urgent' into perf/coreIngo Molnar2011-04-19
| |\ \ \ \ \ \ | | |_|/ / / / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | Merge reason: we'll be queueing up dependent changes. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | perf script: Add more documentation about the -f/--fields parametersArnaldo Carvalho de Melo2011-03-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Using the commit log for 2c9e45f. Cc: David Ahern <daahern@cisco.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Tom Zanussi <tzanussi@gmail.com> LKML-Reference: <new-submission> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * | | | | | perf script: If type not given fields apply to all event typesDavid Ahern2011-03-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow: perf script -f <fields> to be equivalent to: perf script -f trace:<fields> -f sw:<fields> -f hw:<fields> i.e., the specified fields apply to all event types if the type string is not given. The field (-f) arguments are processed in the order received. A later usage can reset a prior request. e.g., -f trace: -f comm,tid,time,sym The first -f suppresses trace events (field list is ""), but then the second invocation sets the fields to comm,tid,time,sym. In this case a warning is given to the user: "Overriding previous field request for all events." Alternativey, consider the order: -f comm,tid,time,sym -f trace: The first -f sets the fields for all events and the second -f suppresses trace events. The user is given a warning message about the override, and the result of the above is that only S/W and H/W events are displayed with the given fields. For the 'wildcard' option if a user selected field is invalid for an event type, a message is displayed to the user that the option is ignored for that type. For example: perf script -f comm,tid,trace 2>&1 | less 'trace' not valid for hardware events. Ignoring. 'trace' not valid for software events. Ignoring. Alternatively, if the type is given an invalid field is specified it is an error. For example: perf script -v -f sw:comm,tid,trace 2>&1 | less 'trace' not valid for software events. At this point usage is displayed, and perf-script exits. Finally, a user may not set fields to none for all event types. i.e., -f "" is not allowed. Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-kernel@vger.kernel.org LPU-Reference: <1300377801-27246-1-git-send-email-daahern@cisco.com> Signed-off-by: David Ahern <daahern@cisco.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * | | | | | Merge branch 'perf/core' of ↵Ingo Molnar2011-03-30
| |\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux-2.6 into perf/core
| | * | | | | | perf probe: Add fastpath to do lookup by function nameLin Ming2011-03-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | v3 -> v2: - Make pubname_search_cb more generic - Add fastpath to find_probes also v2 -> v1: - Don't compare file names with cu_find_realpath(...), instead, compare them with the name returned by dwarf_decl_file(sp_die) The vmlinux file may have thousands of CUs. We can lookup function name from .debug_pubnames section to avoid the slow loop on CUs. 1. Improvement data for find_line_range ./perf stat -e cycles -r 10 -- ./perf probe -k /home/mlin/vmlinux \ -s /home/mlin/linux-2.6 \ --line csum_partial_copy_to_user > tmp.log before patch applied ===================== 847,988,276 cycles 0.355075856 seconds time elapsed after patch applied ===================== 206,102,622 cycles 0.086883555 seconds time elapsed 2. Improvement data for find_probes ./perf stat -e cycles -r 10 -- ./perf probe -k /home/mlin/vmlinux \ -s /home/mlin/linux-2.6 \ --vars csum_partial_copy_to_user > tmp.log before patch applied ===================== 848,490,844 cycles 0.355307901 seconds time elapsed after patch applied ===================== 205,684,469 cycles 0.086694010 seconds time elapsed Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: linux-kernel <linux-kernel@vger.kernel.org> LKML-Reference: <1301041668.14111.52.camel@minggr.sh.intel.com> Signed-off-by: Lin Ming <ming.m.lin@intel.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * | | | | | | perf, x86: P4 PMU - clean up the code a bitCyrill Gorcunov2011-03-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | No change on the functional level, just align the table properly. Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Lin Ming <ming.m.lin@intel.com> LKML-Reference: <4D8FA213.5050108@openvz.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | | | | | Merge branch 'irq-core-for-linus' of ↵Linus Torvalds2011-05-19
|\ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: irq: Export functions to allow modular irq drivers genirq: Uninline and sanity check generic_handle_irq() genirq: Remove pointless ifdefs genirq: Make generic irq chip depend on CONFIG_GENERIC_IRQ_CHIP genirq: Add chip suspend and resume callbacks genirq: Implement a generic interrupt chip genirq: Support per-IRQ thread disabling. genirq: irq_desc: Document preflow_handler and affinity_hint genirq: Update DocBook comments genirq: Forgotten updates/deletions after removal of compat code
| * | | | | | | | irq: Export functions to allow modular irq driversJonathan Cameron2011-05-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Export handle_simple_irq, irq_modify_status, irq_alloc_descs, irq_free_descs and generic_handle_irq to allow their usage in modules. First user is IIO, which wants to be built modular, but needs to be able to create irq chips, allocate and configure interrupt descriptors and handle demultiplexing interrupts. [ tglx: Moved the uninlinig of generic_handle_irq to a separate patch ] Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk> Link: http://lkml.kernel.org/r/%3C1305711544-505-1-git-send-email-jic23%40cam.ac.uk%3E Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | | | | | genirq: Uninline and sanity check generic_handle_irq()Thomas Gleixner2011-05-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | generic_handle_irq() is missing a NULL pointer check for the result of irq_to_desc. This was a not a big problem, but we want to expose it to drivers, so we better have sanity checks in place. Add a return value as well, which indicates that the irq number was valid and the handler was invoked. Based on the pure code move from Jonathan Cameron. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Jonathan Cameron <jic23@cam.ac.uk>
| * | | | | | | | genirq: Remove pointless ifdefsThomas Gleixner2011-05-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kernel/irq/ is only built when CONFIG_GENERIC_HARDIRQS=y. So making code inside of kernel/irq/ conditional on CONFIG_GENERIC_HARDIRQS is pointless. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | | | | | genirq: Make generic irq chip depend on CONFIG_GENERIC_IRQ_CHIPThomas Gleixner2011-05-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Only compile it in when there are users. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arm-kernel@lists.infradead.org
| * | | | | | | | genirq: Add chip suspend and resume callbacksThomas Gleixner2011-04-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These callbacks are only called in the syscore suspend/resume code on interrupt chips which have been registered via the generic irq chip mechanism. Calling those callbacks per irq would be rather icky, but with the generic irq chip mechanism we can call this per registered chip. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arm-kernel@lists.infradead.org
| * | | | | | | | genirq: Implement a generic interrupt chipThomas Gleixner2011-04-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement a generic interrupt chip, which is configurable and is able to handle the most common irq chip implementations. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arm-kernel@lists.infradead.org Tested-by: H Hartley Sweeten <hsweeten@visionengravers.com> Tested-by: Tony Lindgren <tony@atomide.com> Tested-by; Kevin Hilman <khilman@ti.com>
| * | | | | | | | genirq: Support per-IRQ thread disabling.Paul Mundt2011-04-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds support for disabling threading on a per-IRQ basis via the IRQ status instead of the IRQ flow, which is necessary for interrupts that don't follow the natural IRQ flow channels, such as those that are virtually created. The new APIs added are simply: irq_set_thread() irq_set_nothread() which follow the rest of the IRQ status routines. Chained handlers also have IRQ_NOTHREAD set on them automatically, making the lack of threading explicit rather than implicit. Subsequently, the nothread flag can be viewed through the standard genirq debugging facilities. [ tglx: Fixed cleanup fallout ] Signed-off-by: Paul Mundt <lethal@linux-sh.org> Link: http://lkml.kernel.org/r/%3C20110406210135.GF18426%40linux-sh.org%3E Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | | | | | genirq: irq_desc: Document preflow_handler and affinity_hintGeert Uytterhoeven2011-04-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ tglx: Filled in the FIXME place holders ] Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Link: http://lkml.kernel.org/r/%3C1302426113-13808-2-git-send-email-geert%40linux-m68k.org%3E Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | | | | | genirq: Update DocBook commentsGeert Uytterhoeven2011-04-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix some parts to match the actual code. [ tglx: Resolved the FIXMEs Gerd put in ] Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Link: http://lkml.kernel.org/r/%3C1302426113-13808-3-git-send-email-geert%40linux-m68k.org%3E Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: linux-doc@vger.kernel.org
| * | | | | | | | genirq: Forgotten updates/deletions after removal of compat codeGeert Uytterhoeven2011-04-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 0c6f8a8b917ad361319c8ace3e9f28e69bfdb4c1 ("genirq: Remove compat code") removed the compat code, but forgot to update some references in comments and delete some of its documentation. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Link: http://lkml.kernel.org/r/%3C1302426113-13808-1-git-send-email-geert%40linux-m68k.org%3E Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | | | | | | | | Merge branch 'core-locking-for-linus' of ↵Linus Torvalds2011-05-19
|\ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: seqlock: Don't smp_rmb in seqlock reader spin loop watchdog, hung_task_timeout: Add Kconfig configurable default lockdep: Remove cmpxchg to update nr_chain_hlocks lockdep: Print a nicer description for simple irq lock inversions lockdep: Replace "Bad BFS generated tree" message with something less cryptic lockdep: Print a nicer description for irq inversion bugs lockdep: Print a nicer description for simple deadlocks lockdep: Print a nicer description for normal deadlocks lockdep: Print a nicer description for irq lock inversions
| * | | | | | | | | seqlock: Don't smp_rmb in seqlock reader spin loopMilton Miller2011-05-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move the smp_rmb after cpu_relax loop in read_seqlock and add ACCESS_ONCE to make sure the test and return are consistent. A multi-threaded core in the lab didn't like the update from 2.6.35 to 2.6.36, to the point it would hang during boot when multiple threads were active. Bisection showed af5ab277ded04bd9bc6b048c5a2f0e7d70ef0867 (clockevents: Remove the per cpu tick skew) as the culprit and it is supported with stack traces showing xtime_lock waits including tick_do_update_jiffies64 and/or update_vsyscall. Experimentation showed the combination of cpu_relax and smp_rmb was significantly slowing the progress of other threads sharing the core, and this patch is effective in avoiding the hang. A theory is the rmb is affecting the whole core while the cpu_relax is causing a resource rebalance flush, together they cause an interfernce cadance that is unbroken when the seqlock reader has interrupts disabled. At first I was confused why the refactor in 3c22cd5709e8143444a6d08682a87f4c57902df3 (kernel: optimise seqlock) didn't affect this patch application, but after some study that affected seqcount not seqlock. The new seqcount was not factored back into the seqlock. I defer that the future. While the removal of the timer interrupt offset created contention for the xtime lock while a cpu does the additonal work to update the system clock, the seqlock implementation with the tight rmb spin loop goes back much further, and is just waiting for the right trigger. Cc: <stable@vger.kernel.org> Signed-off-by: Milton Miller <miltonm@bga.com> Cc: <linuxppc-dev@lists.ozlabs.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andi Kleen <andi@firstfloor.org> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Anton Blanchard <anton@samba.org> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Link: http://lkml.kernel.org/r/%3Cseqlock-rmb%40mdm.bga.com%3E Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | | | | | | watchdog, hung_task_timeout: Add Kconfig configurable defaultJeff Mahoney2011-04-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch allows the default value for sysctl_hung_task_timeout_secs to be set at build time. The feature carries virtually no overhead, so it makes sense to keep it enabled. On heavily loaded systems, though, it can end up triggering stack traces when there is no bug other than the system being underprovisioned. We use this patch to keep the hung task facility available but disabled at boot-time. The default of 120 seconds is preserved. As a note, commit e162b39a may have accidentally reverted commit fb822db4, which raised the default from 120 seconds to 480 seconds. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Acked-by: Mandeep Singh Baines <msb@google.com> Link: http://lkml.kernel.org/r/4DB8600C.8080000@suse.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | | | lockdep: Remove cmpxchg to update nr_chain_hlocksSteven Rostedt2011-04-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For some reason nr_chain_hlocks is updated with cmpxchg, but this is performed inside of the lockdep global "grab_lock()", which also makes simple modification of this variable atomic. Remove the cmpxchg logic for updating nr_chain_hlocks and simplify the code. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110421014300.727863282@goodmis.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | | | lockdep: Print a nicer description for simple irq lock inversionsSteven Rostedt2011-04-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Lockdep output can be pretty cryptic, having nicer output can save a lot of head scratching. When a simple irq inversion scenario is detected by lockdep (lock A taken in interrupt context but also in thread context without disabling interrupts) we now get the following (hopefully more informative) output: other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(lockA); <Interrupt> lock(lockA); *** DEADLOCK *** Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110421014300.436140880@goodmis.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | | | lockdep: Replace "Bad BFS generated tree" message with something less crypticSteven Rostedt2011-04-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The message of "Bad BFS generated tree" is a bit confusing. Replace it with a more sane error message. Thanks to Peter Zijlstra for helping me come up with a better message. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110421014300.135521252@goodmis.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | | | lockdep: Print a nicer description for irq inversion bugsSteven Rostedt2011-04-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Irq inversion and irq dependency bugs are only subtly different. The diffenerence lies where the interrupt occurred. For irq dependency: irq_disable lock(A) lock(B) unlock(B) unlock(A) irq_enable lock(B) unlock(B) <interrupt> lock(A) The interrupt comes in after it has been established that lock A can be held when taking an irq unsafe lock. Lockdep detects the problem when taking lock A in interrupt context. With the irq_inversion the irq happens before it is established and lockdep detects the problem with the taking of lock B: <interrupt> lock(A) irq_disable lock(A) lock(B) unlock(B) unlock(A) irq_enable lock(B) unlock(B) Since the problem with the locking logic for both of these issues is in actuality the same, they both should report the same scenario. This patch implements that and prints this: other info that might help us debug this: Chain exists of: &rq->lock --> lockA --> lockC Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(lockC); local_irq_disable(); lock(&rq->lock); lock(lockA); <Interrupt> lock(&rq->lock); *** DEADLOCK *** Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110421014259.910720381@goodmis.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | | | lockdep: Print a nicer description for simple deadlocksSteven Rostedt2011-04-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Lockdep output can be pretty cryptic, having nicer output can save a lot of head scratching. When a simple deadlock scenario is detected by lockdep (lock A -> lock A) we now get the following new output: other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(lock)->rlock); lock(&(lock)->rlock); *** DEADLOCK *** Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110421014259.643930104@goodmis.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | | | lockdep: Print a nicer description for normal deadlocksSteven Rostedt2011-04-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The lockdep output can be pretty cryptic, having nicer output can save a lot of head scratching. When a normal deadlock scenario is detected by lockdep (lock A -> lock B and there exists a place where lock B -> lock A) we now get the following new output: other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(lockB); lock(lockA); lock(lockB); lock(lockA); *** DEADLOCK *** On cases where there's a deeper chair, it shows the partial chain that can cause the issue: Chain exists of: lockC --> lockA --> lockB Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(lockB); lock(lockA); lock(lockB); lock(lockC); *** DEADLOCK *** Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110421014259.380621789@goodmis.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | | | lockdep: Print a nicer description for irq lock inversionsSteven Rostedt2011-04-22
| | |_|_|_|/ / / / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Locking order inversion due to interrupts is a subtle problem. When an irq lockiinversion discovered by lockdep it currently reports something like: [ INFO: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected ] ... and then prints out the locks that are involved, as back traces. Judging by lkml feedback developers were routinely confused by what a HARDIRQ->safe to unsafe issue is all about, and sometimes even blew it off as a bug in lockdep. It is not obvious when lockdep prints this message about a lock that is never taken in interrupt context. After explaining the problems that lockdep is reporting, I decided to add a description of the problem in visual form. Now the following is shown: --- other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(lockA); local_irq_disable(); lock(&rq->lock); lock(lockA); <Interrupt> lock(&rq->lock); *** DEADLOCK *** --- The above is the case when the unsafe lock is taken while holding a lock taken in irq context. But when a lock is taken that also grabs a unsafe lock, the call chain is shown: --- other info that might help us debug this: Chain exists of: &rq->lock --> lockA --> lockC Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(lockC); local_irq_disable(); lock(&rq->lock); lock(lockA); <Interrupt> lock(&rq->lock); *** DEADLOCK *** Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20110421014259.132728798@goodmis.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | | | | | | Merge branch 'core-iommu-for-linus' of ↵Linus Torvalds2011-05-19
|\ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86, gart: Rename pci-gart_64.c to amd_gart_64.c x86/amd-iommu: Use threaded interupt handler arch/x86/kernel/pci-iommu_table.c: Convert sprintf_symbol to %pS x86/amd-iommu: Add support for invalidate_all command x86/amd-iommu: Add extended feature detection x86/amd-iommu: Add ATS enable/disable code x86/amd-iommu: Add flag to indicate IOTLB support x86/amd-iommu: Flush device IOTLB if ATS is enabled x86/amd-iommu: Select PCI_IOV with AMD IOMMU driver PCI: Move ATS declarations in seperate header file dma-debug: print information about leaked entry x86/amd-iommu: Flush all internal TLBs when IOMMUs are enabled x86/amd-iommu: Rename iommu_flush_device x86/amd-iommu: Improve handling of full command buffer x86/amd-iommu: Rename iommu_flush* to domain_flush* x86/amd-iommu: Remove command buffer resetting logic x86/amd-iommu: Cleanup completion-wait handling x86/amd-iommu: Cleanup inv_pages command handling x86/amd-iommu: Move inv-dte command building to own function x86/amd-iommu: Move compl-wait command building to own function
| * \ \ \ \ \ \ \ \ Merge branch 'gart/rename' of ↵Ingo Molnar2011-05-17
| |\ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/joro/linux-2.6-iommu into core/iommu
| | * | | | | | | | | x86, gart: Rename pci-gart_64.c to amd_gart_64.cJoerg Roedel2011-05-10
| | | |_|_|_|_|_|_|/ | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This file only contains code relevant for the northbridge gart in AMD processors. This patch renames the file to represent this fact in the filename. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
| * | | | | | | | | Merge branch 'iommu/2.6.40' of ↵Ingo Molnar2011-05-10
| |\ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/joro/linux-2.6-iommu into core/iommu
| | * | | | | | | | | x86/amd-iommu: Use threaded interupt handlerJoerg Roedel2011-05-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move the interupt handling for the iommu into the interupt thread to reduce latencies and prepare interupt handling for pri handling. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
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| | *---. \ \ \ \ \ \ \ \ Merge branches 'dma-debug/next', 'amd-iommu/command-cleanups', ↵Joerg Roedel2011-05-10
| | |\ \ \ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 'amd-iommu/ats' and 'amd-iommu/extended-features' into iommu/2.6.40 Conflicts: arch/x86/include/asm/amd_iommu_types.h arch/x86/kernel/amd_iommu.c arch/x86/kernel/amd_iommu_init.c
| | | | | * | | | | | | | | x86/amd-iommu: Add support for invalidate_all commandJoerg Roedel2011-04-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds support for the invalidate_all command present in new versions of the AMD IOMMU. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
| | | | | * | | | | | | | | x86/amd-iommu: Add extended feature detectionJoerg Roedel2011-04-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds detection of the extended features of an AMD IOMMU. The available features are printed to dmesg on boot. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>