This is a very poorly named feature. I think originally it meant to cover linux only, but the use of it in msan
seems to be about any aarch64 platform. Anyway, this change should be NFC on everything except Android.
llvm-svn: 315389
Summary:
This change removes the dependency on using a std::deque<...> for the
storage of the buffers in the buffer queue. We instead implement a
fixed-size circular buffer that's resilient to exhaustion, and preserves
the semantics of the BufferQueue.
We're moving away from using std::deque<...> for two reasons:
- We want to remove dependencies on the STL for data structures.
- We want the data structure we use to not require re-allocation in
the normal course of operation.
The internal implementation of the buffer queue uses heap-allocated
arrays that are initialized once when the BufferQueue is created, and
re-uses slots in the buffer array as buffers are returned in order.
We also change the lock used in the implementation to a spinlock
instead of a blocking mutex. We reason that since the release operations
now take very little time in the critical section, that a spinlock would
be appropriate.
This change is related to D38073.
This change is a re-submit with the following changes:
- Keeping track of the live buffers with a counter independent of the
pointers keeping track of the extents of the circular buffer.
- Additional documentation of what the data members are meant to
represent.
Reviewers: dblaikie, kpw, pelikan
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D38119
llvm-svn: 314877
Summary:
When the XRay user calls the API to finish writing the log, the thread
which is calling the API still hasn't finished and therefore won't get
its trace written. Add a test for only the main thread to check this.
Reviewers: dberris
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D38493
llvm-svn: 314875
Summary:
This change removes the dependency on using a std::deque<...> for the
storage of the buffers in the buffer queue. We instead implement a
fixed-size circular buffer that's resilient to exhaustion, and preserves
the semantics of the BufferQueue.
We're moving away from using std::deque<...> for two reasons:
- We want to remove dependencies on the STL for data structures.
- We want the data structure we use to not require re-allocation in
the normal course of operation.
The internal implementation of the buffer queue uses heap-allocated
arrays that are initialized once when the BufferQueue is created, and
re-uses slots in the buffer array as buffers are returned in order.
We also change the lock used in the implementation to a spinlock
instead of a blocking mutex. We reason that since the release operations
now take very little time in the critical section, that a spinlock would
be appropriate.
This change is related to D38073.
Reviewers: dblaikie, kpw, pelikan
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D38119
llvm-svn: 314766
Summary:
Write out records about logged function call first arguments. D32840
implements the reading of this in llvm-xray.
Reviewers: dberris
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D32844
llvm-svn: 314378
Summary:
This change starts differentiating tail exits from normal exits. We also
increase the version number of the "naive" log to version 2, which will
be the starting version where these records start appearing. In FDR mode
we treat the tail exits as normal exits, and are thus subject to the
same treatment with regard to record unwriting.
Updating the version number is important to signal older builds of the
llvm-xray tool that do not deal with the tail exit records must fail
early (and that users should only use the llvm-xray tool built after
the support for tail exits to get accurate handling of these records).
Depends on D37964.
Reviewers: kpw, pelikan
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D37965
llvm-svn: 313515
Thesee tests require the integrated assembler which is still in
development / testing for MIPS64. GAS doesn't understand the
section directives produced by XRay, so marking the relevant
tests as unsupported.
llvm-svn: 312628
Summary:
Before this change we seemed to not be running the unit tests, and therefore we
set out to run them. In the process of making this happen we found a divergence
between the implementation and the tests.
This includes changes to both the CMake files as well as the implementation and
headers of the XRay runtime. We've also updated documentation on the changed
functions.
Reviewers: kpw, eizan
Subscribers: mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D37290
llvm-svn: 312202
Summary:
This change introduces versions to the instrumentation map entries we
emit for XRay instrumentaiton points. The status quo for the version is
currently set to 0 (as emitted by the LLVM back-end), and versions will
count up to 255 (unsigned char).
This change is in preparation for supporting the newer version of the
custom event sleds that will be emitted by the LLVM compiler.
While we're here, we take the opportunity to stash more registers and
align the stack properly in the __xray_CustomEvent trampoline.
Reviewers: kpw, pcc, dblaikie
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D36816
llvm-svn: 311524
Summary:
Here we add a build with -ffunction-sections -fdata-sections and
-Wl,--gc-sections to ensure that we're still able to generate XRay
traces.
This is just adding a test, no functional changes.
Differential Revision: https://reviews.llvm.org/D36863
llvm-svn: 311145
The quiet-start.cc test currently fails for arm (and potentially other
platforms). This change limits it to x86_64-linux.
Follow-up to D35789.
llvm-svn: 309538
Summary:
Currently when the XRay runtime is linked into a binary that doesn't
have the instrumentation map, we print a warning unconditionally. This
change attempts to make this behaviour more quiet.
Reviewers: kpw, pelikan
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D35789
llvm-svn: 309534
Summary:
This change introduces two files that show exaples of the
always/never instrument files that can be provided to clang. We don't
add these as defaults yet in clang, which we can do later on (in a
separate change).
We also add a test that makes sure that these apply in the compiler-rt
project tests, and that changes in clang don't break the expectations in
compiler-rt.
Reviewers: pelikan, kpw
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34669
llvm-svn: 306502
This test makes sure we can handle both arg0 and arg1 handling in the
same binary, and making sure that the XRay runtime calls the correct
trampoline when handlers for both of these cases are installed.
llvm-svn: 305660
Summary:
This allows us to do more interesting things with the data available to
C++ methods, to log the `this` pointer.
Depends on D34050.
Reviewers: pelikan
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D34051
llvm-svn: 305545
We only have an implementation in x86_64 that works for the
patching/unpatching and runtime support (trampolines).
Follow-up to D30630.
llvm-svn: 302873
Summary:
This change implements support for the custom event logging sleds and
intrinsics at runtime. For now it only supports handling the sleds in
x86_64, with the implementations for other architectures stubbed out to
do nothing.
NOTE: Work in progress, uploaded for exposition/exploration purposes.
Depends on D27503, D30018, and D33032.
Reviewers: echristo, javed.absar, timshen
Subscribers: mehdi_amini, nemanjai, llvm-commits
Differential Revision: https://reviews.llvm.org/D30630
llvm-svn: 302857
Summary:
This bug is caused by the incorrect handling of return-value registers.
According to OpenPOWER 64-Bit ELF V2 ABI 2.2.5, up to 2 general-purpose
registers are going to be used for return values, and up to 8 floating
point registers or vector registers are going to be used for return
values.
Reviewers: dberris, echristo
Subscribers: nemanjai, llvm-commits
Differential Revision: https://reviews.llvm.org/D33027
llvm-svn: 302691
Summary:
The test fails on PPC, because the address of a function may vary
depending on whether the "taker" shares the same ToC (roughly, in the
same "module") as the function.
Therefore the addresses of the functions taken in func-id-utils.cc may be
different from the addresses taken in xray runtime.
Change the test to be permissive on address comparison.
Reviewers: dberris, echristo
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D33026
llvm-svn: 302686
Follow-up on D32846 to simplify testing and not rely on FileCheck to
test boundary conditions, and instead do all the testing in code
instead.
llvm-svn: 302212
Summary:
This change allows us to provide users and implementers of XRay handlers
a means of converting XRay function id's to addresses. This, in
combination with the facilities provided in D32695, allows users to find
out:
- How many function id's there are defined in the current binary.
- Get the address of the function associated with this function id.
- Patch only specific functions according to their requirements.
While we don't directly provide symbolization support in XRay, having
the function's address lets users determine this information easily
either during runtime, or offline with tools like 'addr2line'.
Reviewers: dblaikie, echristo, pelikan
Subscribers: kpw, llvm-commits
Differential Revision: https://reviews.llvm.org/D32846
llvm-svn: 302210
Summary:
This change allows us to patch/unpatch specific functions using the
function ID. This is useful in cases where implementations might want to
do coverage-style, or more fine-grained control of which functions to
patch or un-patch at runtime.
Depends on D32693.
Reviewers: dblaikie, echristo, kpw
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D32695
llvm-svn: 302112
Summary:
The thread order test fails sometimes my machine independently of standalone
build.
From testing both standalone and in-tree build, I see I configured it wrong.
The other hypothesis for an issue is that cold starts can interfere with whether
record unwriting happens. Once this happens more than once, we can naively
FileCheck on the wrong test output, which compounds the issue.
While "rm blah.* || true" will print to stderr if the glob can't expand, this is
mostly harmless and makes sure earlier failing tests don't sabotage us.
Example failure:
---
header:
version: 1
type: 1
constant-tsc: true
nonstop-tsc: true
cycle-frequency: 3800000000
records:
- { type: 0, func-id: 1, function: 'f1()', cpu: 9, thread: 21377, kind: function-enter, tsc: 2413745203147228 }
- { type: 0, func-id: 1, function: 'f1()', cpu: 9, thread: 21377, kind: function-exit, tsc: 2413745203304238 }
...
The CMAKE related change fixes the expectation that COMPILER_RT_STANDALONE_BUILD will be explicitly FALSE instead
of empty string when it is not "TRUE".
Reviewers: dberris
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D32259
llvm-svn: 300822
Summary:
Tests that generate output with compiler-rt and verify it with the llvm_xray
command (built from the llvm tree) are extremely convenient, but compiler-rt
can be built out of tree and llvm_xray is not built for every target.
This change intends to disable tests for out of tree builds, but does nothing
to detect whether llvm_xray can be found elsewhere on the path, is fresh enough,
or is part of a build target for the in tree build.
Tested:
Tested that this didn't break check-xray. Haven't reproduced bots or standalone
builds.
Reviewers: dberris, kcc
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D32150
llvm-svn: 300716
Summary:
"short" is defined as an xray flag, and buffer rewinding happens for both exits
and tail exits.
I've made the choice to seek backwards finding pairs of FunctionEntry, TailExit
record pairs and erasing them if the FunctionEntry occurred before exit from the
currently exiting function. This is a compromise so that we don't skip logging
tail calls if the function that they call into takes longer our duration.
This works by counting the consecutive function and function entry, tail exit
pairs that proceed the current point in the buffer. The buffer is rewound to
check whether these entry points happened recently enough to be erased.
It is still possible we will omit them if they call into a child function that
is not instrumented which calls a fast grandchild that is instrumented before
doing other processing.
Reviewers: pelikan, dberris
Reviewed By: dberris
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D31345
llvm-svn: 299629
Until llvm-xray starts running/supporting binaries that are not ELF64 we
only run the FDR tests on x86_64-linux. Previous changes caused the
tests to not actually run on x86_64.
Follow-up on D31454.
llvm-svn: 299050
Summary:
This change allows us to do an end-to-end test of the FDR mode
implementation that uses the llvm-xray tooling to verify that what we
are both writing and reading the data in a consistent manner.
Reviewers: kpw, pelikan
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D31454
llvm-svn: 299042
Summary:
This change exercises the end-to-end functionality defined in the FDR
logging implementation. We also prepare for being able to run traces
generated by the FDR logging implementation from being analysed with the
llvm-xray command that comes with the LLVM distribution.
This also unblocks D31385, D31384, and D31345.
Reviewers: kpw, pelikan
Subscribers: llvm-commits, mgorny
Differential Revision: https://reviews.llvm.org/D31452
llvm-svn: 298977
Summary:
rL297000 and rL297003 implemented arg1 logging on amd64 and made
other architectures build. We need to blacklist the new test as well.
Reviewers: dberris, timshen
Reviewed By: dberris
Subscribers: sdardis, llvm-commits
Differential Revision: https://reviews.llvm.org/D30635
llvm-svn: 297238
Temporarily mark the test as unsupported so the powerpc le buildbot
testers can get back to work.
There was a brief discussion of this on the mailing list for r296998.
llvm-svn: 297184
Summary:
Functions with the LOG_ARGS_ENTRY sled kind at their beginning will be handled
in a way to (optionally) pass their first call argument to your logging handler.
For practical and performance reasons, only the first argument is supported, and
only up to 64 bits.
Reviewers: javed.absar, dberris
Reviewed By: dberris
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D29703
llvm-svn: 297000
Summary:
Currently, we assume that applications built with XRay would like to
have the instrumentation sleds patched before main starts. This patch
changes the default so that we do not patch the instrumentation sleds
before main. This default is more helpful for deploying applications in
environments where changing the current default is harder (i.e. on
remote machines, or work-pool-like systems).
This default (not to patch pre-main) makes it easier to selectively run
applications with XRay instrumentation enabled, than with the current
state.
Reviewers: echristo, timshen
Subscribers: mehdi_amini, llvm-commits
Differential Revision: https://reviews.llvm.org/D30396
llvm-svn: 296445
Summary:
In this change we introduce the notion of a "flight data recorder" mode
for XRay logging, where XRay logs in-memory first, and write out data
on-demand as required (as opposed to the naive implementation that keeps
logging while tracing is "on"). This depends on D26232 where we
implement the core data structure for holding the buffers that threads
will be using to write out records of operation.
This implementation only currently works on x86_64 and depends heavily
on the TSC math to write out smaller records to the inmemory buffers.
Also, this implementation defines two different kinds of records with
different sizes (compared to the current naive implementation): a
MetadataRecord (16 bytes) and a FunctionRecord (8 bytes). MetadataRecord
entries are meant to write out information like the thread ID for which
the metadata record is defined for, whether the execution of a thread
moved to a different CPU, etc. while a FunctionRecord represents the
different kinds of function call entry/exit records we might encounter
in the course of a thread's execution along with a delta from the last
time the logging handler was called.
While this implementation is not exactly what is described in the
original XRay whitepaper, this one gives us an initial implementation
that we can iterate and build upon.
Reviewers: echristo, rSerge, majnemer
Subscribers: mehdi_amini, llvm-commits, mgorny
Differential Revision: https://reviews.llvm.org/D27038
llvm-svn: 293015
Summary:
Testing of XRay was occasionally disabled on 32-bit Arm targets (someone assumed that XRay was supported on 64-bit targets only). This patch should fix that problem. Also here the instruction&data cache incoherency problem is fixed, because it may be causing a test to fail.
This patch is one of a series: see also
- https://reviews.llvm.org/D28624
Reviewers: dberris, rengolin
Reviewed By: rengolin
Subscribers: llvm-commits, aemerson, rengolin, dberris, iid_iunknown
Differential Revision: https://reviews.llvm.org/D28623
llvm-svn: 292517
This reverts commit r292211, as it broke the Thumb buldbot with:
clang-5.0: error: the clang compiler does not support '-fxray-instrument
on thumbv7-unknown-linux-gnueabihf'
llvm-svn: 292356
Summary:
Testing of XRay was occasionally disabled on 32-bit Arm targets (someone assumed that XRay was supported on 64-bit targets only). This patch should fix that problem. Also here the instruction&data cache incoherency problem is fixed, because it may be causing a test to fail.
This patch is one of a series: see also
- https://reviews.llvm.org/D28624
Reviewers: dberris, rengolin
Reviewed By: rengolin
Subscribers: llvm-commits, aemerson, rengolin, dberris, iid_iunknown
Differential Revision: https://reviews.llvm.org/D28623
llvm-svn: 292211
Summary: This patch attempts to fix test patching-unpatching.cc . The new code flushes the instruction cache after modifying the program at runtime.
Reviewers: dberris, rengolin, pelikan, rovka
Subscribers: rovka, llvm-commits, iid_iunknown, aemerson
Differential Revision: https://reviews.llvm.org/D27996
llvm-svn: 291568
Evgeniy Stepanov