The following attribute is set when synthesising samples in
timed decoding mode:
attr.sample_type |= PERF_SAMPLE_TIME;
This results in new samples that appear to have timestamps but
because we don't assign any timestamps to the samples, when the
resulting inject file is opened again, the synthesised samples
will be on the wrong side of the MMAP or COMM events.
For example, this results in the samples being associated with
the perf binary, rather than the target of the record:
perf record -e cs_etm/@tmc_etr0/u top
perf inject -i perf.data -o perf.inject --itrace=i100il
perf report -i perf.inject
Where 'Command' == perf should show as 'top':
# Overhead Command Source Shared Object Source Symbol Target Symbol Basic Block Cycles
# ........ ....... .................... ...................... ...................... ..................
#
31.08% perf [unknown] [.] 0x000000000040c3f8 [.] 0x000000000040c3e8 -
If the perf.data file is opened directly with perf, without the
inject step, then this already works correctly because the
events are synthesised after the COMM and MMAP events and
no second sorting happens. Re-sorting only happens when opening
the perf.inject file for the second time so timestamps are
needed.
Using the timestamp from the AUX record mirrors the current
behaviour when opening directly with perf, because the events
are generated on the call to cs_etm__process_queues().
The ETM trace could optionally contain time stamps, but there is
no way to correlate this with the kernel time. So, the best available
time value is that of the AUX_RECORD header. This patch uses
the timestamp from the header for all the samples. The ordering of the
samples are implicit in the trace and thus is fine with respect to
relative ordering.
Reviewed-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Co-developed-by: Al Grant <al.grant@arm.com>
Signed-off-by: Al Grant <al.grant@arm.com>
Signed-off-by: James Clark <james.clark@arm.com>
Acked-by: Suzuki K Poulos <suzuki.poulose@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Branislav Rankov <branislav.rankov@arm.com>
Cc: Denis Nikitin <denik@chromium.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: coresight@lists.linaro.org
Link: https://lore.kernel.org/r/20210510143248.27423-3-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When building selftests, the build system will install uapi linux
headers at usr/include in kernel source's root directory. When building
with a different output folder, the headers will be installed at
kselftests/usr/include.
Add both paths so we can build the tests using up-to-date headers.
Currently, this is uncommon to happen since it's rare to find a
build system with an outdated futex header, but it happens
when testing new futex operations.
Signed-off-by: André Almeida <andrealmeid@collabora.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210427135328.11013-2-andrealmeid@collabora.com
AUX area data is not processed by 'perf record' and consequently the
--timestamp-boundary option may result in no values for "time of first
sample" and "time of last sample". However there are non-sample events
that can be used instead, namely 'itrace_start' and 'aux'.
'itrace_start' is issued before tracing starts, and 'aux' is issued
every time data is ready.
Implement tool callbacks for those two for 'perf record', to update the
timestamp boundary.
Example:
$ perf record -e intel_pt//u --timestamp-boundary uname
Linux
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.022 MB perf.data ]
$ perf script --header-only | grep "time of"
# time of first sample : 4574.835541
# time of last sample : 4574.835907
$ perf script --itrace=be -F-ip | head -1
uname 13752 [001] 4574.835589: 1 branches:uH:
$ perf script --itrace=be -F-ip | tail -1
uname 13752 [001] 4574.835867: 1 branches:uH:
$
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20210503064222.5319-1-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
VM Time Correlation means determining if each TSC packet belongs to a VM
Guest or the Host. When the trace is "in context" that is indicated by
the NR flag in the PIP packet. However, when tracing kernel-only,
userspace only, or using address filters, the trace can be "out of context"
in which case timing packets are produced but not PIP packets.
Nevertheless, it is very unlikely the VM Guest timestamps will be in
the same range as the Host timestamps. Host time ranges are established
by a starting side-band event timestamp, and subsequently by the buffer
timestamp, written when the buffer is copied to the perf.data file.
This patch supports updating the VM Guest timestamp packets, assuming an
unchanging (during perf record) VMX TSC Offset and no VMX TSC scaling.
Furthermore, it is possible to determine what the VMX TSC Offset is,
although not necessarily at the start. The dry-run option lets that
information be determined so that the user can pass it to a subsequent
run. For more detail, refer to the example in the Intel PT documentation
in a subsequent patch.
VM Time Correlation is also performed on the TSC value in PEBs-via-PT
records.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: https://lore.kernel.org/r/20210430070309.17624-12-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Even when VMX TSC Offset is not changing (during perf record), different
virtual machines can have different TSC Offsets. There is a Virtual Machine
Control Structure (VMCS) for each virtual CPU, the address of which is
reported to Intel PT in the VMCS packet. We do not know which VMCS belongs
to which virtual machine, so use a tree to keep track of VMCS information.
Then the decoder will be able to use the current VMCS value to look up the
current TSC Offset.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: https://lore.kernel.org/r/20210430070309.17624-9-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Intel PT timestamps are affected by virtualization. Add a new option
that will allow the Intel PT decoder to correlate the timestamps and
translate the virtual machine timestamps to host timestamps.
The advantages of making this a separate step, rather than a part of
normal decoding are that it is simpler to implement, and it needs to
be done only once.
This patch adds only the option. Later patches add Intel PT support.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: https://lore.kernel.org/r/20210430070309.17624-6-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Teach objtool about the the low bits in the struct static_key pointer.
That is, the low two bits of @key in:
struct jump_entry {
s32 code;
s32 target;
long key;
}
as found in the __jump_table section. Since @key has a relocation to
the variable (to be resolved by the linker), the low two bits will be
reflected in the relocation's addend.
As such, find the reloc and store the addend, such that we can access
these bits.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210506194158.028024143@infradead.org
Currently objtool has 5 hashtables and sizes them 16 or 20 bits
depending on the --vmlinux argument.
However, a single side doesn't really work well for the 5 tables,
which among them, cover 3 different uses. Also, while vmlinux is
larger, there is still a very wide difference between a defconfig and
allyesconfig build, which again isn't optimally covered by a single
size.
Another aspect is the cost of elf_hash_init(), which for large tables
dominates the runtime for small input files. It turns out that all it
does it assign NULL, something that is required when using malloc().
However, when we allocate memory using mmap(), we're guaranteed to get
zero filled pages.
Therefore, rewrite the whole thing to:
1) use more dynamic sized tables, depending on the input file,
2) avoid the need for elf_hash_init() entirely by using mmap().
This speeds up a regular kernel build (100s to 98s for
x86_64-defconfig), and potentially dramatically speeds up vmlinux
processing.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210506194157.452881700@infradead.org
This patch provides support for setting and copying core scheduling
'task cookies' between threads (PID), processes (TGID), and process
groups (PGID).
The value of core scheduling isn't that tasks don't share a core,
'nosmt' can do that. The value lies in exploiting all the sharing
opportunities that exist to recover possible lost performance and that
requires a degree of flexibility in the API.
From a security perspective (and there are others), the thread,
process and process group distinction is an existent hierarchal
categorization of tasks that reflects many of the security concerns
about 'data sharing'. For example, protecting against cache-snooping
by a thread that can just read the memory directly isn't all that
useful.
With this in mind, subcommands to CREATE/SHARE (TO/FROM) provide a
mechanism to create and share cookies. CREATE/SHARE_TO specify a
target pid with enum pidtype used to specify the scope of the targeted
tasks. For example, PIDTYPE_TGID will share the cookie with the
process and all of it's threads as typically desired in a security
scenario.
API:
prctl(PR_SCHED_CORE, PR_SCHED_CORE_GET, tgtpid, pidtype, &cookie)
prctl(PR_SCHED_CORE, PR_SCHED_CORE_CREATE, tgtpid, pidtype, NULL)
prctl(PR_SCHED_CORE, PR_SCHED_CORE_SHARE_TO, tgtpid, pidtype, NULL)
prctl(PR_SCHED_CORE, PR_SCHED_CORE_SHARE_FROM, srcpid, pidtype, NULL)
where 'tgtpid/srcpid == 0' implies the current process and pidtype is
kernel enum pid_type {PIDTYPE_PID, PIDTYPE_TGID, PIDTYPE_PGID, ...}.
For return values, EINVAL, ENOMEM are what they say. ESRCH means the
tgtpid/srcpid was not found. EPERM indicates lack of PTRACE permission
access to tgtpid/srcpid. ENODEV indicates your machines lacks SMT.
[peterz: complete rewrite]
Signed-off-by: Chris Hyser <chris.hyser@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Don Hiatt <dhiatt@digitalocean.com>
Tested-by: Hongyu Ning <hongyu.ning@linux.intel.com>
Tested-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/20210422123309.039845339@infradead.org
Daniel Borkmann says:
====================
pull-request: bpf 2021-05-11
The following pull-request contains BPF updates for your *net* tree.
We've added 13 non-merge commits during the last 8 day(s) which contain
a total of 21 files changed, 817 insertions(+), 382 deletions(-).
The main changes are:
1) Fix multiple ringbuf bugs in particular to prevent writable mmap of
read-only pages, from Andrii Nakryiko & Thadeu Lima de Souza Cascardo.
2) Fix verifier alu32 known-const subregister bound tracking for bitwise
operations and/or/xor, from Daniel Borkmann.
3) Reject trampoline attachment for functions with variable arguments,
and also add a deny list of other forbidden functions, from Jiri Olsa.
4) Fix nested bpf_bprintf_prepare() calls used by various helpers by
switching to per-CPU buffers, from Florent Revest.
5) Fix kernel compilation with BTF debug info on ppc64 due to pahole
missing TCP-CC functions like cubictcp_init, from Martin KaFai Lau.
6) Add a kconfig entry to provide an option to disallow unprivileged
BPF by default, from Daniel Borkmann.
7) Fix libbpf compilation for older libelf when GELF_ST_VISIBILITY()
macro is not available, from Arnaldo Carvalho de Melo.
8) Migrate test_tc_redirect to test_progs framework as prep work
for upcoming skb_change_head() fix & selftest, from Jussi Maki.
9) Fix a libbpf segfault in add_dummy_ksym_var() if BTF is not
present, from Ian Rogers.
10) Fix tx_only micro-benchmark in xdpsock BPF sample with proper frame
size, from Magnus Karlsson.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
As discussed in [0], stop emitting static variables in BPF skeletons to avoid
issues with name-conflicting static variables across multiple
statically-linked BPF object files.
Users using static variables to pass data between BPF programs and user-space
should do a trivial one-time switch according to the following simple rules:
- read-only `static volatile const` variables should be converted to
`volatile const`;
- read/write `static volatile` variables should just drop `static volatile`
modifiers to become global variables/symbols. To better handle older Clang
versions, such newly converted global variables should be explicitly
initialized with a specific value or `= 0`/`= {}`, whichever is
appropriate.
[0] https://lore.kernel.org/bpf/CAEf4BzZo7_r-hsNvJt3w3kyrmmBJj7ghGY8+k4nvKF0KLjma=w@mail.gmail.com/T/#m664d4b0d6b31ac8b2669360e0fc2d6962e9f5ec1
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210507054119.270888-5-andrii@kernel.org
In preparation of skipping emitting static variables in BPF skeletons, switch
all current selftests uses of static variables to pass data between BPF and
user-space to use global variables.
All non-read-only `static volatile` variables become just plain global
variables by dropping `static volatile` part.
Read-only `static volatile const` variables, though, still require `volatile`
modifier, otherwise compiler will ignore whatever values are set from
user-space.
Few static linker tests are using name-conflicting static variables to
validate that static linker still properly handles static variables and
doesn't trip up on name conflicts.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210507054119.270888-4-andrii@kernel.org
For better future extensibility add per-file linker options. Currently
the set of available options is empty. This changes bpf_linker__add_file()
API, but it's not a breaking change as bpf_linker APIs hasn't been released
yet.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210507054119.270888-3-andrii@kernel.org
A misspelled git-grep regex revealed that smp_mb__after_spinlock()
was misspelled in explanation.txt. This commit adds the missing "_".
Fixes: 1c27b644c0 ("Automate memory-barriers.txt; provide Linux-kernel memory model")
[ paulmck: Apply Alan Stern commit-log feedback. ]
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Currently, if a torture scenario requires more CPUs than are present
on the build system, kvm.sh and friends limit the CPUs available to
that scenario. This makes total sense when the build system and the
system running the scenarios are one and the same, but not so much when
remote systems might well have more CPUs.
This commit therefore introduces a --remote flag to kvm.sh that suppresses
this CPU-limiting behavior, and causes kvm-remote.sh to use this flag.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
In a long-duration kvm-remote.sh run, almost all of the remote accesses will
be simple file-existence checks. These are thus the most likely to be caught
out by network failures, which do happen from time to time.
This commit therefore takes a first step towards tolerating temporary
network outages by making the file-existence checks repeat in the face of
such an outage. They also print a message every minute during a outage,
allowing the user to take appropriate action.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
This commit adds the BUSTED-BOOST rcutorture scenario, which can be
used to test rcutorture's ability to test RCU priority boosting.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Some of the code invoked directly and indirectly from kvm.sh parses
the output of commands. This parsing assumes English, which can cause
failures if the user has set some other language. In a few cases,
there are language-independent commands available, but this is not
always the case. Therefore, as an alternative to polyglot parsing,
this commit sets the LANG environment variable to en_US.UTF-8.
Reported-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Grepping for "CPU" on lscpu output isn't always successful, depending
on the local language setting. As a result, the build can be aborted
early with:
"make: the '-j' option requires a positive integer argument"
This commit therefore uses the human-language-independent approach
available via the getconf command, both in kvm-build.sh and in
kvm-remote.sh.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Currently, kvm-find-errors.sh assumes that if "--buildonly" appears in
the log file, then the run did builds but ran no kernels. This breaks
with kvm-remote.sh, which uses kvm.sh to do a build, then kvm-again.sh
to run the kernels built on remote systems. This commit therefore adds
a check for a kvm-remote.sh run.
While in the area, this commit checks for "--build-only" as well as
"--build-only".
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Given remote rcutorture runs, it is quite possible that the build system
will have fewer CPUs than the system(s) running the actual test scenarios.
In such cases, using the number of CPUs on the test systems can overload
the build system, slowing down the build or, worse, OOMing the build
system. This commit therefore uses the build system's CPU count to set
N in "make -jN", and by tradition sets "N" to double the CPU count.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
This commit reduces duplicate code by making kvm.sh use the new
kvm-end-run-stats.sh script rather than taking its historical approach
of open-coding it.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
This commit abstractst the end-of-run summary from kvm-again.sh, and,
while in the area, brings its format into line with that of kvm.sh.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
The kvm-again.sh script relies on shell comments added to the qemu-cmd
file, but this means that code extracting values from the QEMU command in
this file must grep out those commment. Which kvm-recheck-rcu.sh failed
to do, which destroyed its grace-period-per-second calculation. This
commit therefore adds the needed "grep -v '^#'" to kvm-recheck-rcu.sh.
Fixes: 315957cad4 ("torture: Prepare for splitting qemu execution from kvm-test-1-run.sh")
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
This commit adds a kvm-remote.sh script that prepares a tarball that
is then downloaded to the remote system(s) and executed. The user is
responsible for having set up the remote systems to run qemu, but all the
kernel builds are done on the system running the kvm-remote.sh script.
The user is also responsible for setting up the remote systems so that
ssh can be run non-interactively, given that ssh is used to poll the
remote systems in order to detect completion of each batch.
See the script's header comment for usage information.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
It is no longer possible to disable CPU hotplug in many configurations,
which means that the CONFIG_HOTPLUG_CPU=n lines in rcuscale's Kconfig
options are just a source of useless diagnostics. In addition, rcuscale
doesn't do CPU-hotplug operations in any case. This commit therefore
changes these lines to read CONFIG_HOTPLUG_CPU=y.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
It is no longer possible to disable CPU hotplug in many configurations,
which means that the CONFIG_HOTPLUG_CPU=n lines in refscale's Kconfig
options are just a source of useless diagnostics. In addition, refscale
doesn't do CPU-hotplug operations in any case. This commit therefore
changes these lines to read CONFIG_HOTPLUG_CPU=y.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
This commit saves a few lines of code by making kvm-again.sh use the
"scenarios" file rather than the "batches" file, both of which are
generated by kvm.sh.
This results in a break point because new versions of kvm-again.sh cannot
handle "res" directories produced by old versions of kvm.sh, which lack
the "scenarios" file. In the unlikely event that this becomes a problem,
a trivial script suffices to convert the "batches" file to a "scenarios"
file, and this script may be easily extracted from kvm.sh.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
This commit adds "--dryrun scenarios" to kvm.sh, which prints something
like this:
1. TREE03
2. TREE07
3. SRCU-P SRCU-N
4. TREE01 TRACE01
5. TREE02 TRACE02
6. TREE04 RUDE01 TASKS01
7. TREE05 TASKS03 SRCU-T SRCU-U
8. TASKS02 TINY01 TINY02 TREE09
This format is more convenient for scripts that run batches of scenarios.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
