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We don't have a test to check that MSG_MORE won't let us merge records
of different types across sendmsg calls.
Add new tests that check:
- MSG_MORE is only allowed for DATA records
- a pending DATA record gets closed and pushed before a non-DATA
record is processed
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Link: https://patch.msgid.link/b34feeadefe8a997f068d5ed5617afd0072df3c0.1760432043.git.sd@queasysnail.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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This commit adds two tests. The first is the most basic unit test:
make sure an empty queue peeks as empty, and when we put one element
in the queue, make sure peek returns that element.
However, even this simple test is a little complicated by the different
behavior of scx_bpf_dsq_insert in different calling contexts:
- insert is for direct dispatch in enqueue
- insert is delayed when called from select_cpu
In this case we split the insert and the peek that verifies the
result between enqueue/dispatch.
Note: An alternative would be to call `scx_bpf_dsq_move_to_local` on an
empty queue, which in turn calls `flush_dispatch_buf`, in order to flush
the buffered insert. Unfortunately, this is not viable within the
enqueue path, as it attempts a voluntary context switch within an RCU
read-side critical section.
The second test is a stress test that performs many peeks on all DSQs
and records the observed tasks.
Signed-off-by: Ryan Newton <newton@meta.com>
Reviewed-by: Christian Loehle <christian.loehle@arm.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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The builtin DSQ queue data structures are meant to be used by a wide
range of different sched_ext schedulers with different demands on these
data structures. They might be per-cpu with low-contention, or
high-contention shared queues. Unfortunately, DSQs have a coarse-grained
lock around the whole data structure. Without going all the way to a
lock-free, more scalable implementation, a small step we can take to
reduce lock contention is to allow a lockless, small-fixed-cost peek at
the head of the queue.
This change allows certain custom SCX schedulers to cheaply peek at
queues, e.g. during load balancing, before locking them. But it
represents a few extra memory operations to update the pointer each
time the DSQ is modified, including a memory barrier on ARM so the write
appears correctly ordered.
This commit adds a first_task pointer field which is updated
atomically when the DSQ is modified, and allows any thread to peek at
the head of the queue without holding the lock.
Signed-off-by: Ryan Newton <newton@meta.com>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
Reviewed-by: Christian Loehle <christian.loehle@arm.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Add a simple test for the corner case not currently covered by the
sticky fingers quirk. Because it's a corner case test, we only test this
on a couple of devices, not on all of them because the value of adding
the same test over and over is rather moot.
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
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Convert test_cpu to use the newly added values_close_report() helper
to print detailed diagnostics when a tolerance check fails. This
provides clearer insight into deviations while run in the CI.
Signed-off-by: Sebastian Chlad <sebastian.chlad@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Some cgroup selftests, such as test_cpu, occasionally fail by a very
small margin and if run in the CI context, it is useful to have detailed
diagnostic output to understand the deviation.
Introduce a values_close_report() helper which performs the same
comparison as values_close(), but prints detailed information when the
values differ beyond the allowed tolerance.
Signed-off-by: Sebastian Chlad <sebastian.chlad@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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Add TEST_ASSERT_EVSEL to dump the failing evsel in the event of a
failure.
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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Add TEST_ASSERT_EVLIST to dump the failing evlist in the event of a
failure.
Add the macro to a number of tests not currently checking the evlist
length.
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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Just have a single test_hw_config helper that strips extended type
information in the case of hardware and hardware cache events.
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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Without a PMU perf matches an event against any PMU with the
event. Unfortunately some PMU drivers advertise a "cycles" event which
is typically just a core event. As tests assume a core event, switch
to use "cpu-cycles" that avoids the overloaded "cycles" event on
troublesome PMUs and is so far not overloaded. Note, on x86 this
changes a legacy event into a sysfs one.
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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In the event parse string, switch "cpu" to "default_core" and then
rewrite this to the first core PMU name prior to parsing. This enables
testing with a PMU on hybrid x86 and other systems that don't use
"cpu" for the core PMU name. The name "default_core" is already used
by jevents. Update test expectations to match.
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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Without a PMU perf matches an event against any PMU with the
event. Unfortunately some PMU drivers advertise a "cycles" event which
is typically just a core event. Switch to using "cpu-cycles" which is
an indentical legacy event but avoids the multiple PMU confusion
introduced by the PMU drivers. Note, on x86 cpu-cycles is also a sysfs
event but cycles isn't.
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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Switch from the test's assert_hw/test_config to the common
evsel__match code that appropriately handles events with both legacy
and sysfs/json encoding.
For tests asserting that a config value matches that placed in the
perf_event_attr just directly compare the config values.
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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Ensure both the perf_event_attr and alternate_hw_config are checked in
the match. Don't mask the config if the perf_event_attr isn't a
HARDWARE or HW_CACHE event. Add common early exit cases.
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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Rather than wildcard matching the cycles event specify only the core
PMUs. This avoids potentially loading unnecessary uncore PMUs.
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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Rather than distributing the code doing similar things to
evlist__new_default, use the one implementation so that paranoia and
wildcard scanning can be optimized.
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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Rather than distributing the code doing similar things to
evlist__new_default, use the one implementation so that paranoia and
wildcard scanning can be optimized.
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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Now that legacy hardware and cache events are in json, having the
lexer match the specific event is no longer necessary and generic PMU
parsing can take place. Because of this remove the specific term
parsing, event adding, and passing of alternate_hw_config which was
now always PERF_COUNT_HW_MAX.
This mirrors a similar change for software events in commit 6e9fa4131abb
("perf parse-events: Remove non-json software events").
With no hard coded legacy hardware or cache events the wild card, case
insensitivity, etc. is consistent for events. This does, however, mean
events like cycles will wild card against all PMUs. A change does the
same was originally posted and merged from:
https://lore.kernel.org/r/20240416061533.921723-10-irogers@google.com
and reverted by Linus in commit 4f1b067359ac ("Revert "perf
parse-events: Prefer sysfs/JSON hardware events over legacy"") due to
his dislike for the cycles behavior on ARM. Earlier patches in this
series make perf record event opening failures non-fatal and hide the
cycles event's failure to open on ARM in perf record, so it is
expected the behavior will now be transparent in perf record. perf
stat with a cycles event will wildcard open the event on all PMUs. As
cycles is a "default event", the perf stat behavior for default events
was updated to only open them on core/software PMUs.
The change to support legacy events with PMUs was done to clean up
Intel's hybrid PMU implementation. Having sysfs/json events with
increased priority to legacy was requested by Mark Rutland
<mark.rutland@arm.com> to fix Apple-M PMU issues wrt broken legacy
events on that PMU. It was requested that RISC-V be able to add events
to the perf tool json so the PMU driver didn't need to map legacy
events to config encodings:
https://lore.kernel.org/lkml/20240217005738.3744121-1-atishp@rivosinc.com/
A previous series of patches decreasing legacy hardware event
priorities was posted in:
https://lore.kernel.org/lkml/20250416045117.876775-1-irogers@google.com/
Namhyung Kim <namhyung@kernel.org> mentioned that hardware and
software events can be implemented similarly:
https://lore.kernel.org/lkml/aIJmJns2lopxf3EK@google.com/
Tested-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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Now legacy hardware events are in json there's no need for a specific
printing routine that previously served for both hardware and software
events. The associated event_symbols_hw is also removed. To support
the previous filtered version use an event glob of "legacy hardware"
which matches the topic of the json events.
Tested-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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Now legacy cache events are in json there's no need for a specific
printing routine. To support the previous filtered version use an
event glob of "legacy cache" which matches the topic of the json
events.
Tested-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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The legacy-hardware.json is added containing hardware events similarly
to the software.json file. A difference is that for the software PMU
the name is known and matches sysfs. In the legacy-hardware.json no
Unit/PMU is specified for the events meaning default_core is used and
the events will appear for all core PMUs.
There are potentially 1216 legacy cache events, rather than list them
in a json file add a make_legacy_cache.py helper to generate them.
By using json for legacy hardware and cache events: descriptions of
the events can be added; events can be marked as deprecated, such as
those misleadingly named l2 (deprecated is also used to mark all
events that weren't previously displayed in perf list); and the name
lookup becomes case insensitive.
The C string encoding all the perf events and metrics is increased in
size by 123,499 bytes which will increase the perf binary size. Later
changes will remove hard coded event parsing for legacy hardware and
cache events, turning parsing overhead into a binary search during
event lookup.
That event descriptions are based off of those in perf_event_open man
page, credit to Vince Weaver <vincent.weaver@maine.edu>.
Tested-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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Add support to finding/adding events from the default_core event
table. If an event already exists from sysfs/json then the
default_core configuration is saved in the legacy_terms string. Lazily
use the legacy_terms string to set a legacy hardware or cache event as
deprecated if the core PMU doesn't support it. Use the legacy terms
string to set the alternate_hw_config, avoiding the value needing to
be passed from the parse_events parser.
Tested-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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Add json LegacyConfigCode and LegacyCacheCode values that translate to
legacy-hardware-config and legacy-cache-config event terms
respectively.
Add perf_pmu__default_core_events_table as a means to find a
default_core event table that will later contain legacy events.
In situations like hypervisors it is more likely that tables will be
NULL. Rather than testing in the calling PMU code, early exit in the
pmu-event.c routines.
Tested-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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Add the PMU terms legacy-hardware-config and
legacy-cache-config. These terms are similar to the config term in
that their values are assigned to the perf_event_attr config
value. They differ in that the PMU type is switched to be either
PERF_TYPE_HARDWARE or PERF_TYPE_HW_CACHE, and the PMU type is moved
into the extended type information of the config value. This will
allow later patches to add legacy events to json.
An example use of the terms is in the following:
```
$ perf stat -vv -e 'cpu/legacy-hardware-config=1/,cpu/legacy-cache-config=0x10001/' true
Using CPUID GenuineIntel-6-8D-1
Attempt to add: cpu/legacy-hardware-config=0x1/
..after resolving event: cpu/legacy-hardware-config=0x1/
Attempt to add: cpu/legacy-cache-config=0x10001/
..after resolving event: cpu/legacy-cache-config=0x10001/
Control descriptor is not initialized
------------------------------------------------------------
perf_event_attr:
type 0 (PERF_TYPE_HARDWARE)
size 136
config 0x1 (PERF_COUNT_HW_INSTRUCTIONS)
sample_type IDENTIFIER
read_format TOTAL_TIME_ENABLED|TOTAL_TIME_RUNNING
disabled 1
inherit 1
enable_on_exec 1
------------------------------------------------------------
sys_perf_event_open: pid 994937 cpu -1 group_fd -1 flags 0x8 = 3
------------------------------------------------------------
perf_event_attr:
type 3 (PERF_TYPE_HW_CACHE)
size 136
config 0x10001 (PERF_COUNT_HW_CACHE_RESULT_MISS | PERF_COUNT_HW_CACHE_OP_READ | PERF_COUNT_HW_CACHE_L1I)
sample_type IDENTIFIER
read_format TOTAL_TIME_ENABLED|TOTAL_TIME_RUNNING
disabled 1
inherit 1
enable_on_exec 1
------------------------------------------------------------
sys_perf_event_open: pid 994937 cpu -1 group_fd -1 flags 0x8 = 4
cpu/legacy-hardware-config=1/: -1: 1364046 414756 414756
cpu/legacy-cache-config=0x10001/: -1: 57453 414756 414756
cpu/legacy-hardware-config=1/: 1364046 414756 414756
cpu/legacy-cache-config=0x10001/: 57453 414756 414756
Performance counter stats for 'true':
1,364,046 cpu/legacy-hardware-config=1/
57,453 cpu/legacy-cache-config=0x10001/
0.001988593 seconds time elapsed
0.002194000 seconds user
0.000000000 seconds sys
```
Tested-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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Factor existing functionality in perf_pmu__name_from_config into a
helper that will be used in later patches.
Tested-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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The FILE argument was necessary for the scanner but now that
functionality is not being used we can switch to just using
io__getline which should cut down on stdio buffer usage.
Tested-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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Now the events file isn't directly parsed from a FILE but stored in a
string prior to parsing, remove the FILE argument to the associated
scanner functions as they only ever pass NULL.
Tested-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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When an event/alias is created for a PMU the terms are eagerly parsed
using parse_events_terms. For a command like perf stat or perf record,
the particular event/alias will be found, the terms parsed, the
terms cloned for use in the event parsing, and then the terms used to
configure the perf_event_attr. Events/aliases may be eagerly loaded,
such as from sysfs or in perf list, in which case the aliases terms
will be little or never used. To avoid redundant work, to avoid
cloning, and to reduce memory overhead, hold the terms for an event as
a string until they need handling as a term list. This may introduce
duplicate parsing if an event is repeated in a list, but this
situation is expected to be uncommon.
Measuring the number of instructions before and after with a sysfs
event and perf stat, there is a minor reduction in the number of
instructions executed by 0.3%.
Tested-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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The jevents command expects all json files to be organized under a
single directory. When generating json files from scripts (to reduce
laborious copy and paste in the json) we don't want to generate the
json into the source directory if there is an OUTPUT directory
specified. This change adds a GEN_JSON for this case where the
GEN_JSON copies the JSON files to OUTPUT, only when OUTPUT is
specified. The Makefile.perf clean code is updated to clean up this
directory when present.
This patch is part of:
https://lore.kernel.org/lkml/20240926173554.404411-12-irogers@google.com/
which was similarly adding support for generating json in scripts for
the consumption of jevents.py.
Tested-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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Whilst for many tools it is an expected behavior that failure to open
a perf event is a failure, ARM decided to name PMU events the same as
legacy events and then failed to rename such events on a server uncore
SLC PMU. As perf's default behavior when no PMU is specified is to
open the event on all PMUs that advertise/"have" the event, this
yielded failures when trying to make the priority of legacy and
sysfs/json events uniform - something requested by RISC-V and ARM. A
legacy event user on ARM hardware may find their event opened on an
uncore PMU which for perf record will fail. Arnaldo suggested skipping
such events which this patch implements. Rather than have the skipping
conditional on running on ARM, the skipping is done on all
architectures as such a fundamental behavioral difference could lead
to problems with tools built/depending on perf.
An example of perf record failing to open events on x86 is:
```
$ perf record -e data_read,cycles,LLC-prefetch-read -a sleep 0.1
Error:
Failure to open event 'data_read' on PMU 'uncore_imc_free_running_0' which will be removed.
The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (data_read).
"dmesg | grep -i perf" may provide additional information.
Error:
Failure to open event 'data_read' on PMU 'uncore_imc_free_running_1' which will be removed.
The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (data_read).
"dmesg | grep -i perf" may provide additional information.
Error:
Failure to open event 'LLC-prefetch-read' on PMU 'cpu' which will be removed.
The LLC-prefetch-read event is not supported.
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 2.188 MB perf.data (87 samples) ]
$ perf report --stats
Aggregated stats:
TOTAL events: 17255
MMAP events: 284 ( 1.6%)
COMM events: 1961 (11.4%)
EXIT events: 1 ( 0.0%)
FORK events: 1960 (11.4%)
SAMPLE events: 87 ( 0.5%)
MMAP2 events: 12836 (74.4%)
KSYMBOL events: 83 ( 0.5%)
BPF_EVENT events: 36 ( 0.2%)
FINISHED_ROUND events: 2 ( 0.0%)
ID_INDEX events: 1 ( 0.0%)
THREAD_MAP events: 1 ( 0.0%)
CPU_MAP events: 1 ( 0.0%)
TIME_CONV events: 1 ( 0.0%)
FINISHED_INIT events: 1 ( 0.0%)
cycles stats:
SAMPLE events: 87
```
If all events fail to open then the perf record will fail:
```
$ perf record -e LLC-prefetch-read true
Error:
Failure to open event 'LLC-prefetch-read' on PMU 'cpu' which will be removed.
The LLC-prefetch-read event is not supported.
Error:
Failure to open any events for recording
```
As an evlist may have dummy events that open when all command line
events fail we ignore dummy events when detecting if at least some
events open. This still permits the dummy event on its own to be used
as a permission check:
```
$ perf record -e dummy true
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.046 MB perf.data ]
```
but allows failure when a dummy event is implicilty inserted or when
there are insufficient permissions to open it:
```
$ perf record -e LLC-prefetch-read -a true
Error:
Failure to open event 'LLC-prefetch-read' on PMU 'cpu' which will be removed.
The LLC-prefetch-read event is not supported.
Error:
Failure to open any events for recording
```
As the first parsed event in an evlist is marked as tracking, removing
this event can remove tracking from the evlist, removing mmap events
and breaking symbolization. To avoid this, if a tracking event is
removed then the next event has tracking added.
The issue with legacy events is that on RISC-V they want the driver to
not have mappings from legacy to non-legacy config encodings for each
vendor/model due to size, complexity and difficulty to update. It was
reported that on ARM Apple-M? CPUs the legacy mapping in the driver
was broken and the sysfs/json events should always take precedent,
however, it isn't clear this is still the case. It is the case that
without working around this issue a legacy event like cycles without a
PMU can encode differently than when specified with a PMU - the
non-PMU version favoring legacy encodings, the PMU one avoiding legacy
encodings. Legacy events are also case sensitive while sysfs/json
events are not.
The patch removes events and then adjusts the idx value for each
evsel. This is done so that the dense xyarrays used for file
descriptors, etc. don't contain broken entries.
On ARM it could be common following this change to see a lot of
warnings for the cycles event due to many ARM PMUs advertising the
cycles event (ARM inconsistently have events bus_cycles and then
cycles implying CPU cycles, they also sometimes have a cpu_cycles
event). As cycles is a popular event, avoid potentially spamming users
with error messages on ARM when there are multiple cycles events in
the evlist, the error is still shown when verbose is enabled.
Prior versions without adding the tracking data and not warning for
cycles on ARM was:
Suggested-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Tested-by: James Clark <james.clark@linaro.org>
Tested-by: Leo Yan <leo.yan@arm.com>
Tested-by: Atish Patra <atishp@rivosinc.com>
Tested-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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Without a PMU perf matches an event against any PMU with the
event. Unfortunately some PMU drivers advertise a "cycles" event which
is typically just a core event. To make perf's behavior consistent,
just look up default events with their designated PMU types.
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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Scan the software PMU first rather than last as it is the least likely
to fail the probe. Specifying the software PMU by name was enabled by
commit 9957d8c801fe ("perf jevents: Add common software event
json"). For hardware events, add core PMU names when getting events to
probe so that not all PMUs are scanned. For example, when legacy
events support wildcards and for the event "cycles:u" on x86, we want
to only scan the "cpu" PMU and not all uncore PMUs for the event too.
Tested-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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The term list when adding an event to a PMU is expected to have the
event name for the alias lookup. Also, set found_supported so that
-EINVAL isn't returned.
Fixes: 62593394f66a ("perf parse-events: Legacy cache names on all
PMUs and lower priority")
Tested-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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Since v4.1 kernel, a new interface for ftrace called "tracefs" was
introduced, which is usually mounted in /sys/kernel/tracing. Therefore,
tracing files can now be accessed via either the legacy path
/sys/kernel/debug/tracing or the newer path /sys/kernel/tracing.
Signed-off-by: Fushuai Wang <wangfushuai@baidu.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Tested-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
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We started getting a crash in BPF CI, which seems to originate from
test_parse_test_list_file() test and is happening at this line:
ASSERT_OK(strcmp("test_with_spaces", set.tests[0].name), "test 0 name");
One way we can crash there is if set.cnt zero, which is checked for with
ASSERT_EQ() above, but we proceed after this regardless of the outcome.
Instead of crashing, we should bail out with test failure early.
Similarly, if parse_test_list_file() fails, we shouldn't be even looking
at set, so bail even earlier if ASSERT_OK() fails.
Fixes: 64276f01dce8 ("selftests/bpf: Test_progs can read test lists from file")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Ihor Solodrai <ihor.solodrai@linux.dev>
Link: https://lore.kernel.org/r/20251014202037.72922-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Add a klp-build script which automates the generation of a livepatch
module from a source .patch file by performing the following steps:
- Builds an original kernel with -function-sections and
-fdata-sections, plus objtool function checksumming.
- Applies the .patch file and rebuilds the kernel using the same
options.
- Runs 'objtool klp diff' to detect changed functions and generate
intermediate binary diff objects.
- Builds a kernel module which links the diff objects with some
livepatch module init code (scripts/livepatch/init.c).
- Finalizes the livepatch module (aka work around linker wreckage)
using 'objtool klp post-link'.
Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
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In preparation for klp-build, enable "classic" objtool to work on
livepatch modules:
- Avoid duplicate symbol/section warnings for prefix symbols and the
.static_call_sites and __mcount_loc sections which may have already
been extracted by klp diff.
- Add __klp_funcs to the IBT function pointer section whitelist.
- Prevent KLP symbols from getting incorrectly classified as cold
subfunctions.
Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
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The prefix symbol creation code currently ignores all errors, presumably
because some functions don't have the leading NOPs.
Shuffle the code around a bit, improve the error handling and document
why some errors are ignored.
Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
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Livepatch needs some ELF magic which linkers don't like:
- Two relocation sections (.rela*, .klp.rela*) for the same text
section.
- Use of SHN_LIVEPATCH to mark livepatch symbols.
Unfortunately linkers tend to mangle such things. To work around that,
klp diff generates a linker-compliant intermediate binary which encodes
the relevant KLP section/reloc/symbol metadata.
After module linking, the .ko then needs to be converted to an actual
livepatch module. Introduce a new klp post-link subcommand to do so.
Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
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Add a --debug option to klp diff which prints cloning decisions and an
indented dependency tree for all cloned symbols and relocations. This
helps visualize which symbols and relocations were included and why.
Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
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Add a new klp diff subcommand which performs a binary diff between two
object files and extracts changed functions into a new object which can
then be linked into a livepatch module.
This builds on concepts from the longstanding out-of-tree kpatch [1]
project which began in 2012 and has been used for many years to generate
livepatch modules for production kernels. However, this is a complete
rewrite which incorporates hard-earned lessons from 12+ years of
maintaining kpatch.
Key improvements compared to kpatch-build:
- Integrated with objtool: Leverages objtool's existing control-flow
graph analysis to help detect changed functions.
- Works on vmlinux.o: Supports late-linked objects, making it
compatible with LTO, IBT, and similar.
- Simplified code base: ~3k fewer lines of code.
- Upstream: No more out-of-tree #ifdef hacks, far less cruft.
- Cleaner internals: Vastly simplified logic for symbol/section/reloc
inclusion and special section extraction.
- Robust __LINE__ macro handling: Avoids false positive binary diffs
caused by the __LINE__ macro by introducing a fix-patch-lines script
(coming in a later patch) which injects #line directives into the
source .patch to preserve the original line numbers at compile time.
Note the end result of this subcommand is not yet functionally complete.
Livepatch needs some ELF magic which linkers don't like:
- Two relocation sections (.rela*, .klp.rela*) for the same text
section.
- Use of SHN_LIVEPATCH to mark livepatch symbols.
Unfortunately linkers tend to mangle such things. To work around that,
klp diff generates a linker-compliant intermediate binary which encodes
the relevant KLP section/reloc/symbol metadata.
After module linking, a klp post-link step (coming soon) will clean up
the mess and convert the linked .ko into a fully compliant livepatch
module.
Note this subcommand requires the diffed binaries to have been compiled
with -ffunction-sections and -fdata-sections, and processed with
'objtool --checksum'. Those constraints will be handled by a klp-build
script introduced in a later patch.
Without '-ffunction-sections -fdata-sections', reliable object diffing
would be infeasible due to toolchain limitations:
- For intra-file+intra-section references, the compiler might
occasionally generated hard-coded instruction offsets instead of
relocations.
- Section-symbol-based references can be ambiguous:
- Overlapping or zero-length symbols create ambiguity as to which
symbol is being referenced.
- A reference to the end of a symbol (e.g., checking array bounds)
can be misinterpreted as a reference to the next symbol, or vice
versa.
A potential future alternative to '-ffunction-sections -fdata-sections'
would be to introduce a toolchain option that forces symbol-based
(non-section) relocations.
Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
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Add a --debug-checksum=<funcs> option to the check subcommand to print
the calculated checksum of each instruction in the given functions.
This is useful for determining where two versions of a function begin to
diverge.
Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
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In preparation for the objtool klp diff subcommand, add a command-line
option to generate a unique checksum for each function. This will
enable detection of functions which have changed between two versions of
an object file.
Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
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In preparation for the objtool klp diff subcommand, add an
ANNOTATE_DATA_SPECIAL macro which annotates special section entries so
that objtool can determine their size and location and extract them
when needed.
Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
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... for reading annotation types.
Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
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Add interface to enable the creation of a new ELF file.
Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
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elf_create_rela_section() is quite limited in that it requires the
caller to know how many relocations need to be allocated up front.
In preparation for the objtool klp diff subcommand, allow an arbitrary
number of relocations to be created and initialized on demand after
section creation.
Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
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In preparation for the objtool klp diff subcommand, refactor
elf_add_string() by adding a new elf_add_data() helper which allows the
adding of arbitrary data to a section.
Make both interfaces global so they can be used by the upcoming klp diff
code.
Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
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In preparation for the objtool klp diff subcommand, broaden the
elf_create_section() interface to give callers more control and reduce
duplication of some subtle setup logic.
While at it, make elf_create_rela_section() global so sections can be
created by the upcoming klp diff code.
Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
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In preparation for the objtool klp diff subcommand, broaden the
elf_create_symbol() interface to give callers more control and reduce
duplication of some subtle setup logic.
While at it, make elf_create_symbol() and elf_create_section_symbol()
global so sections can be created by the upcoming klp diff code.
Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
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