Mac kext performance tracing #281
There are no files selected for viewing
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,63 @@ | ||
| #include "PerformanceTracing.hpp" | ||
| #include <sys/types.h> | ||
| #include <stdatomic.h> | ||
| #include <IOKit/IOUserClient.h> | ||
|
|
||
| PerfTracingProbe profile_probes[Probe_Count]; | ||
|
|
||
| void PerfTracing_Init() | ||
| { | ||
| for (size_t i = 0; i < Probe_Count; ++i) | ||
|
Member
There was a problem hiding this comment. Should
Contributor
Author
There was a problem hiding this comment. I've been trying to minimise the amount of conditionally compiled code as @sanoursa was uneasy about having too much of it due to the potential of it going stale if it's not well exercised. Given the Init functions are only called once, this seemed a relatively benign one to always allow to run. |
||
| { | ||
| PerfTracing_ProbeInit(&profile_probes[i]); | ||
| } | ||
| } | ||
|
|
||
| void PerfTracing_ProbeInit(PerfTracingProbe* probe) | ||
|
pmj marked this conversation as resolved.
|
||
| { | ||
| *probe = PerfTracingProbe{ .min = UINT64_MAX }; | ||
| } | ||
|
|
||
| IOReturn PerfTracing_ExportDataUserClient(IOExternalMethodArguments* arguments) | ||
| { | ||
| #if PRJFS_PERFORMANCE_TRACING_ENABLE | ||
| if (arguments->structureOutput == nullptr || arguments->structureOutputSize != sizeof(profile_probes)) | ||
| { | ||
| return kIOReturnBadArgument; | ||
| } | ||
|
|
||
| memcpy(arguments->structureOutput, profile_probes, sizeof(profile_probes)); | ||
| return kIOReturnSuccess; | ||
| #else | ||
| return kIOReturnUnsupported; | ||
| #endif | ||
| } | ||
|
|
||
| void PerfTracing_RecordSample(PerfTracingProbe* probe, uint64_t startTime, uint64_t endTime) | ||
| { | ||
| uint64_t interval = endTime - startTime; | ||
|
|
||
| atomic_fetch_add(&probe->numSamples1, 1); | ||
| atomic_fetch_add(&probe->sum, interval); | ||
|
|
||
| __uint128_t intervalSquared = interval; | ||
| intervalSquared *= intervalSquared; | ||
| atomic_fetch_add(&probe->sumSquares, intervalSquared); | ||
|
|
||
| // Update minimum sample if necessary | ||
| { | ||
| uint64_t oldMin = atomic_load(&probe->min); | ||
| while (interval < oldMin && !atomic_compare_exchange_weak(&probe->min, &oldMin, interval)) | ||
| {} | ||
| } | ||
|
|
||
| // Update maximum sample if necessary | ||
| { | ||
| uint64_t oldMax = atomic_load(&probe->max); | ||
| while (interval > oldMax && !atomic_compare_exchange_weak(&probe->max, &oldMax, interval)) | ||
| {} | ||
| } | ||
|
|
||
| atomic_fetch_add(&probe->numSamples2, 1); | ||
| } | ||
|
|
||
Oops, something went wrong.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
What's the impact of this change?
Uh oh!
There was an error while loading. Please reload this page.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
The
<ProfileAction>refers to the "Profile" scheme in Xcode. You can't run/profile kexts directly from Xcode of course, but if you select "Product" -> "Build For" -> "Profiling" it will build using the configuration specified here. So with that Xcode command you can (a) quickly check that your code still builds with profiling enabled, and (b) easily build a profiling-enabled kext you can copy to your target machine without manually messing about with the macro.There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
Ok thanks!