Summary:
This change removes the ad-hoc implementation used by llvm-xray's
`convert` subcommand to generate JSON encoded catapult (AKA Chrome
Trace Viewer) trace output, to instead use the JSON encoder now in the
Support library.
Reviewers: kpw, zturner, eizan
Reviewed By: kpw
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D50129
llvm-svn: 338834
Summary:
llvm-xray changes:
- account-mode - process-id {...} shows after thread-id
- convert-mode - process {...} shows after thread
- parses FDR and basic mode pid entries
- Checks version number for FDR log parsing.
Basic logging changes:
- Update header version from 2 -> 3
FDR logging changes:
- Update header version from 2 -> 3
- in writeBufferPreamble, there is an additional PID Metadata record (after thread id record and tsc record)
Test cases changes:
- fdr-mode.cc, fdr-single-thread.cc, fdr-thread-order.cc modified to catch process id output in the log.
Reviewers: dberris
Reviewed By: dberris
Subscribers: hiraditya, llvm-commits, #sanitizers
Differential Revision: https://reviews.llvm.org/D49153
llvm-svn: 336974
NFC here, this just raises some platform specific ifdef hackery
out of a class and creates proper platform-independent typedefs
for the relevant things. This allows these typedefs to be
reused in other places without having to reinvent this preprocessor
logic.
llvm-svn: 334294
Provide some free functions to reduce verbosity of endian-writing
a single value, and replace the endianness template parameter with
a field.
Part of PR37466.
Differential Revision: https://reviews.llvm.org/D47032
llvm-svn: 332757
Summary:
This brings the filenames in accordance to the style guide and LLVM
conventions for C++ filenames.
As suggested by rnk@ in D46068.
Reviewers: rnk
Subscribers: mgorny, mgrang, llvm-commits
Differential Revision: https://reviews.llvm.org/D46301
llvm-svn: 331321
Summary:
r327219 added wrappers to std::sort which randomly shuffle the container before sorting.
This will help in uncovering non-determinism caused due to undefined sorting
order of objects having the same key.
To make use of that infrastructure we need to invoke llvm::sort instead of std::sort.
Note: This patch is one of a series of patches to replace *all* std::sort to llvm::sort.
Refer the comments section in D44363 for a list of all the required patches.
Reviewers: JDevlieghere, zturner, echristo, dberris, friss
Reviewed By: echristo
Subscribers: gbedwell, llvm-commits
Differential Revision: https://reviews.llvm.org/D45141
llvm-svn: 328943
Summary:
Processing 2 GB XRay traces with "llvm-xray convert -symbolize" needs to
go over each trace record and symbolize the function name refered to by
its ID. Currently this happens by asking the LLVM symbolizer code every
single time. A simple cache can save around 30 minutes of processing of
that trace.
llvm-xray's resident memory usage increased negligibly with this cache.
Reviewers: dberris
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D43896
llvm-svn: 326407
Summary:
It was a copy-paste typo, sorting only to the 90th percentile twice.
Now, it only sorts the array prefix once, and extracts what we need.
Reviewers: dberris, kpw, eizan
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D42690
llvm-svn: 323800
Minimal tool to convert xray traces to Chrome's Trace Event Format.
Summary:
Make use of Chrome Trace Event format's Duration events and stack frame dict to
produce Json files that chrome://tracing can visualize from xray function call
traces. Trace Event format is more robust and has several features like
argument logging, function categorization, multi process traces, etc. that we
can add as needed. Duration events cover an important base case.
Part of this change is rearranging the code so that the TrieNode data structure
can be used from multiple tools and can carry parameterized baggage on the
nodes. I put the actual behavior changes in llvm-xray convert exclusively.
Exploring the trace of instrumented llc was pretty nifty if overwhelming.
I can envision this being very useful for analyzing contention scenarios or
tuning parameters like batch sizes in a producer consumer queue. For more
targeted traces likemthis, let's talk about how we want to approach trace
pruning.
Reviewers: dberris, pelikan
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D39362
llvm-svn: 317531
Summary:
As the first step to allow analysis and visualization of xray collected data,
allow using the llvm-xray stacks tool to emit a complete listing of stacks in
the format consumable by a flamegraph tool.
Possible follow up formats include chrome trace viewer format and sql load
files.
As a POC, I'm able to generate flamegraphs of an xray instrumented llc compiling
hello world.
Reviewers: dberris, pelikan
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D38650
llvm-svn: 315635
Summary:
A new FDR metadata record will support logging a function call argument;
appending multiple metadata records will represent a sequence of arguments
meaning that "holes" are not representable by the buffer format. Each
call argument is currently a 64-bit value (useful for "this" pointers and
synchronization objects).
If present, we put this argument to the function call "entry" record it
belongs to, and alter its type to notify the user of its presence.
Reviewers: dberris
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D32840
llvm-svn: 314269
Summary:
This change adds support for explicit tail-exit records to be written by
the XRay runtime. This lets us differentiate the tail exit
records/events in the log, and allows us to treat those exit events
especially in the future. For now we allow printing those out in YAML
(and reading them in).
Reviewers: kpw, pelikan
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D37964
llvm-svn: 313514
Most callers were not expecting the exit(0) and trying to exit with a
different value.
This also adds back the call to cl::PrintHelpMessage in llvm-ar.
llvm-svn: 312761
Second try after fixing a code san problem with iterator reference types.
This change introduces a subcommand to the llvm-xray tool called
"stacks" which allows for analysing XRay traces provided as inputs and
accounting time to stacks instead of just individual functions. This
gives us a more precise view of where in a program the latency is
actually attributed.
The tool uses a trie data structure to keep track of the caller-callee
relationships as we process the XRay traces. In particular, we keep
track of the function call stack as we enter functions. While we're
doing this we're adding nodes in a trie and indicating a "calls"
relatinship between the caller (current top of the stack) and the callee
(the new top of the stack). When we push function ids onto the stack, we
keep track of the timestamp (TSC) for the enter event.
When exiting functions, we are able to account the duration by getting
the difference between the timestamp of the exit event and the
corresponding entry event in the stack. This works even if we somehow
miss the exit events for intermediary functions (i.e. if the exit event
is not cleanly associated with the enter event at the top of the stack).
The output of the tool currently provides just the top N leaf functions
that contribute the most latency, and the top N stacks that have the
most frequency. In the future we can provide more sophisticated query
mechanisms and potentially an export to database feature to make offline
analysis of the stack traces possible with existing tools.
Differential revision: D34863
llvm-svn: 312733
This change introduces a subcommand to the llvm-xray tool called
"stacks" which allows for analysing XRay traces provided as inputs and
accounting time to stacks instead of just individual functions. This
gives us a more precise view of where in a program the latency is
actually attributed.
The tool uses a trie data structure to keep track of the caller-callee
relationships as we process the XRay traces. In particular, we keep
track of the function call stack as we enter functions. While we're
doing this we're adding nodes in a trie and indicating a "calls"
relatinship between the caller (current top of the stack) and the callee
(the new top of the stack). When we push function ids onto the stack, we
keep track of the timestamp (TSC) for the enter event.
When exiting functions, we are able to account the duration by getting
the difference between the timestamp of the exit event and the
corresponding entry event in the stack. This works even if we somehow
miss the exit events for intermediary functions (i.e. if the exit event
is not cleanly associated with the enter event at the top of the stack).
The output of the tool currently provides just the top N leaf functions
that contribute the most latency, and the top N stacks that have the
most frequency. In the future we can provide more sophisticated query
mechanisms and potentially an export to database feature to make offline
analysis of the stack traces possible with existing tools.
llvm-svn: 312426
Summary:
Before this patch, llvm-xray account will assume that thread stacks will
not be empty. Unfortunately there are cases where an instrumented
function will see a call to `fork()` which will cause the child process
to not see the start of the function, but only see the end of the
function. The tooling cannot assume that threads will always have
perfect stacks, and so we change it to support this reality.
Reviewers: dblaikie
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D31870
llvm-svn: 312204
This creates a new library called BinaryFormat that has all of
the headers from llvm/Support containing structure and layout
definitions for various types of binary formats like dwarf, coff,
elf, etc as well as the code for identifying a file from its
magic.
Differential Revision: https://reviews.llvm.org/D33843
llvm-svn: 304864
Summary:
This is a tool for comparing the function graphs produced by the
llvm-xray graph too. It takes the form of a new subcommand of the
llvm-xray tool 'graph-diff'.
This initial version of the patch is very rough, but it is close to
feature complete.
Depends on D29363
Reviewers: dblaikie, dberris
Reviewed By: dberris
Subscribers: mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D29320
llvm-svn: 301160
Summary:
This allows us to, if the symbol names are available in the binary, be
able to provide the function name in the YAML output.
Reviewers: dblaikie, pelikan
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D32153
llvm-svn: 300624
Summary:
Assertions assuming that function calls may not have zero durations do
not seem to hold in the wild. There are valid cases where the conversion
of the tsc counters end up becoming zero-length durations. These
assertions don't really hold and the algorithms don't need those to be
true for them to work.
Reviewers: dblaikie, echristo
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D31519
llvm-svn: 299150
Summary:
Currently the llvm-xray commandline tool fails to handle the case for
when no subcommand is provided in a graceful manner. This fixes that to
print the help message explaining the subcommands and the available
options.
Reviewers: pcc, pelikan
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D31409
llvm-svn: 298975
Summary:
In Preparation for graph comparison, this patch breaks out the color
choice code from xray-graph into a library and adds polynomials for
the Sequential and Difference sets from ColorBrewer.
Depends on D29005
Reviewers: dblaikie, chandlerc, dberris
Reviewed By: dberris
Subscribers: chandlerc, llvm-commits, mgorny
Differential Revision: https://reviews.llvm.org/D29363
llvm-svn: 296210
Summary:
The file type packs function trace data onto disk from potentially multiple
threads that are aggregated and flushed during the course of an instrumented
program's runtime.
It is named FDR mode or Flight Data recorder as an analogy to plane
blackboxes, which instrument a running system without access to IO.
The writer code is defined in compiler-rt in xray_fdr_logging.h/cc
Reviewers: rSerge, kcc, dberris
Reviewed By: dberris
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D29697
llvm-svn: 295397
Summary:
The YAML output produced by llvm-xray is supposed to be wrapped at the
arbitrary default of 70 columns set by `yaml:Output`. Unfortunately,
the wrapping is rather unpredictable, and can easily go past the set
number of columns, depending on the execution environment.
To make the YAML output environment-independent, disable wrapping
instead.
Reviewers: dberris
Reviewed By: dberris
Subscribers: fhahn, llvm-commits
Differential Revision: https://reviews.llvm.org/D29962
llvm-svn: 295116
Summary:
In preparation for graph comparison and filtering, this is a library for
representing graphs in LLVM. This will enable easier encapsulation and reuse
of graphs in llvm-xray.
Depends on D28999, D28225
Reviewers: dblaikie, dberris
Reviewed By: dberris
Subscribers: mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D29005
llvm-svn: 294717
Summary:
In preparation for graph comparison and filtering, this is a library for
representing graphs in LLVM. This will enable easier encapsulation and reuse
of graphs in llvm-xray.
Depends on D28999, D28225
Reviewers: dblaikie, dberris
Reviewed By: dberris
Subscribers: mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D29005
llvm-svn: 294713
Summary:
This change implements the instrumentation map loading library which can
understand both YAML-defined instrumentation maps, and ELF 64-bit object
files that have the XRay instrumentation map section. We break it out
into a library on its own to allow for other applications to deal with
the XRay instrumentation map defined in XRay-instrumented binaries.
This type provides both raw access to the logical representation of the
instrumentation map entries as well as higher level functions for
converting a function ID into a function address.
At this point we only support ELF64 binaries and YAML-defined XRay
instrumentation maps. Future changes should extend this to support
32-bit ELF binaries, as well as other binary formats (like MachO).
As part of this change we also migrate all uses of the extraction logic
that used to be defined in tools/llvm-xray/ to use this new type and
interface for loading from files. We also remove the flag from the
`llvm-xray` tool that required users to specify the type of the
instrumentation map file being provided to instead make the library
auto-detect the file type.
Reviewers: dblaikie
Subscribers: mgorny, varno, llvm-commits
Differential Revision: https://reviews.llvm.org/D29319
llvm-svn: 293721
Summary:
A patch to enable the llvm-xray graph subcommand to color edges and
vertices based on statistics and to annotate vertices with statistics.
Depends on D27243
Reviewers: dblaikie, dberris
Reviewed By: dberris
Subscribers: mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D28225
llvm-svn: 293031
Here we define the `graph` subcommand which generates a graph from the function
call information and uses it to present the call information graphically with
additional annotations.
Reviewers: dblaikie, dberris
Differential Revision: https://reviews.llvm.org/D27243
llvm-svn: 292156
Dean Michael Berris