It's not necessary to log the error adjustment every time it happens. It's
sufficient to log it when the clock error is too large.
PiperOrigin-RevId: 696922088
Previous threshold (1ms for warning logs) is still too spammy.
Now we only log at warning for deltas above 5ms. Deltas between 1ms and 5ms
are logged at info.
PiperOrigin-RevId: 658859819
It is an idea of running codespell as part of our presubmit checks.
Before enabling it for new changes, let's fix what it has found.
Signed-off-by: Andrei Vagin <avagin@gmail.com>
This introduces a `metric.FieldValue` struct type that wraps a string.
All metric interfaces that deal with field values have been updated to use
pointers to this type instead of strings.
The intent of this change is to make it more obvious that field values must
be passed using references. Prior to this change, this was done using string
pointer comparisons. Now this must be done by using a pointer to the same
`metric.FieldValue` struct.
The struct type still externally exposes its string so that it can be referred
to in value function callbacks by "custom" metrics. (Though there are no
current uses of callback metrics with fields.)
PiperOrigin-RevId: 527030738
This optimizes both increments and lookup operations.
It does so using the following:
- For metrics of potential cardinality larger than 48, it will switch to using
a map rather than linear search for mapping field value combinations to the
index that combination corresponds to in the flattened list of values.
For metrics of cardinality 48 or smaller, linear search is still used as it
is still faster (and also still faster than binary search), as determined by
benchmarks.
- All field values are checked for pointer uniqueness (i.e. the pointer to the
start of each field value string must be unique). This is then used for
faster matching: instead of comparing whole strings (and needing to hash
them, in the case of doing map-based lookups), it compares pointer values.
In the context of this metric library, because all field values must be
pre-declared ahead of time, keeping references to these pre-declared strings
should always be possible. This is enforced: it will `panic` if the metric
user does not do this. In practice, this is easy to do by using `const`
strings for all metric values. This change does just that for existing
metrics with string fields.
From benchmarks, this speeds up the time to take a snapshot of existing
metrics by -8.35%. With the unimplemented syscall counter metric, this
optimization reduces the slowdown of adding this metric from +4,250% to
a still-large but much more manageable +290%. A further optimization
(cl/524419591) will reduce this overhead further before re-introducing the
unimplemented syscall counter metric.
PiperOrigin-RevId: 526134756
For all trivial and zero frame-sized functions, we now require an explicit
NOFRAME annotation as the heuristic has changed. See go.dev/cl/466316.
Most of these functions do not *require* NOFRAME, but this change encodes
the existing behavior in order to avoid accidental bugs or regressions.
PiperOrigin-RevId: 513946210
The vDSO calls are much faster.
For exeample, here are results of read_benchmark_test_tmpfs_kvm before and
after this change:
Before:
BM_Read/65536/real_time 7309 ns 7260 ns 82640 bytes_per_second=8.35016G/s
After:
BM_Read/65536/real_time 2065 ns 2080 ns 346151 bytes_per_second=29.558G/s
PiperOrigin-RevId: 409547486
Removes package syserror and moves still relevant code to either linuxerr
or to syserr (to be later removed).
Internal errors are converted from random types to *errors.Error types used
in linuxerr. Internal errors are in linuxerr/internal.go.
PiperOrigin-RevId: 390724202
This change makes the checklocks analyzer considerable more powerful, adding:
* The ability to traverse complex structures, e.g. to have multiple nested
fields as part of the annotation.
* The ability to resolve simple anonymous functions and closures, and perform
lock analysis across these invocations. This does not apply to closures that
are passed elsewhere, since it is not possible to know the context in which
they might be invoked.
* The ability to annotate return values in addition to receivers and other
parameters, with the same complex structures noted above.
* Ignoring locking semantics for "fresh" objects, i.e. objects that are
allocated in the local frame (typically a new-style function).
* Sanity checking of locking state across block transitions and returns, to
ensure that no unexpected locks are held.
Note that initially, most of these findings are excluded by a comprehensive
nogo.yaml. The findings that are included are fundamental lock violations.
The changes here should be relatively low risk, minor refactorings to either
include necessary annotations to simplify the code structure (in general
removing closures in favor of methods) so that the analyzer can be easily
track the lock state.
This change additional includes two changes to nogo itself:
* Sanity checking of all types to ensure that the binary and ast-derived
types have a consistent objectpath, to prevent the bug above from occurring
silently (and causing much confusion). This also requires a trick in
order to ensure that serialized facts are consumable downstream. This can
be removed with https://go-review.googlesource.com/c/tools/+/331789 merged.
* A minor refactoring to isolation the objdump settings in its own package.
This was originally used to implement the sanity check above, but this
information is now being passed another way. The minor refactor is preserved
however, since it cleans up the code slightly and is minimal risk.
PiperOrigin-RevId: 382613300
Remove three syserror entries duplicated in linuxerr. Because of the
linuxerr.Equals method, this is a mere change of return values from
syserror to linuxerr definitions.
Done with only these three errnos as CLs removing all grow to a significantly
large size.
PiperOrigin-RevId: 382173835
The presence of multiple packages in a single directory sometimes
confuses `go mod`, producing output like:
go: downloading gvisor.dev/gvisor v0.0.0-20210601174640-77dc0f5bc94d
$GOMODCACHE/gvisor.dev/gvisor@v0.0.0-20210601174640-77dc0f5bc94d/pkg/linewriter/linewriter.go:21:2: found packages sync (aliases.go) and seqatomic (generic_atomicptr_unsafe.go) in $GOMODCACHE/gvisor.dev/gvisor@v0.0.0-20210601174640-77dc0f5bc94d/pkg/sync
imports.go:67:2: found packages tcp (accept.go) and rcv (rcv_test.go) in $GOMODCACHE/gvisor.dev/gvisor@v0.0.0-20210601174640-77dc0f5bc94d/pkg/tcpip/transport/tcp
PiperOrigin-RevId: 376956213
Usually ARM counter-timer frequency is range from 1-50Mhz which is
much less than that on x86, so we calibrate defaultOverheadCycles
for ARM.
Signed-off-by: howard zhang <howard.zhang@arm.com>
The newly added Weirdness metric with fields should be used instead of them.
Simple query for weirdness metric: http://shortn/_DGNk0z2Up6
PiperOrigin-RevId: 370578132
Weirdness metric contains fields to track the number of clock fallback,
partial result and vsyscalls. This metric will avoid the overhead of
having three different metrics (fallbackMetric, partialResultMetric,
vsyscallCount).
PiperOrigin-RevId: 369970218
Nicolas LacasseandgVisor bot
Andrei Vagin
Etienne PerotandgVisor bot
Adin ScannellandgVisor bot
Kevin KrakauerandgVisor bot
Ayush RanjanandgVisor bot
Andrei VaginandgVisor bot
Zach KoopmansandgVisor bot
Jamie LiuandgVisor bot
Tamir DubersteinandgVisor bot
howard zhang
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