Skip to content

Tracefs location #710

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
adamtassier wants to merge 5 commits into
base: master
Choose a base branch
from
Open

Tracefs location #710

Show file tree
Hide file tree
Changes from 3 commits
Commits
Show all changes
5 commits
Select commit Hold shift + click to select a range
75bee5f
fix: Query /sys/kernel/tracing/ for tracing support instead of /sys/k…
adamtassier Apr 15, 2025
e49008a
feat: reflect in tooltip that 'enable off-cpu profiling' does not req…
adamtassier Apr 15, 2025
262cd7d
Check /sys/kernel/debug/tracing if /sys/kernel/tracing is accessible
adamtassier May 8, 2025
1d452dd
Remove fallback to /sys/kernel/debug/tracing for tracefs
adamtassier May 9, 2025
b7959f3
Remove lambda now that were only checking one location
adamtassier May 9, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
10 changes: 6 additions & 4 deletions src/recordhost.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -69,7 +69,7 @@ QByteArray perfBuildOptions(const QString& perfPath)

bool canTrace(const QString& path)
{
const QFileInfo info(QLatin1String("/sys/kernel/debug/tracing/") + path);
const QFileInfo info(QLatin1String("/sys/kernel/tracing/") + path);
if (!info.isDir() || !info.isReadable()) {
return false;
}
Expand Down Expand Up @@ -116,10 +116,12 @@ bool privsAlreadyElevated()
struct stat buf;
return stat(path, &buf) == 0 && ((buf.st_mode & 07777) & required) == required;
};
static const auto paths = {"/sys/kernel/debug", "/sys/kernel/debug/tracing"};
isElevated = std::all_of(paths.begin(), paths.end(), checkPerms);

return isElevated;
if (checkPerms("/sys/kernel/tracing")) {
return true;
}
// tracing used to be mounted on /sys/kernel/debug/ on older systems
return checkPerms("/sys/kernel/debug/tracing");
}

RecordHost::PerfCapabilities fetchLocalPerfCapabilities(const QString& perfPath)
Expand Down
6 changes: 4 additions & 2 deletions src/recordpage.ui
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -265,7 +265,8 @@
<item row="2" column="0">
<widget class="QLabel" name="offCpuLabel">
<property name="toolTip">
<string>Record scheduler switch events. This enables off-CPU profiling to measure sleep times etc. This requires elevated privileges.</string>
<string>Record scheduler switch events. This enables off-CPU profiling to measure sleep times etc.
This requires elevated privileges or both /sys/kernel/tracing to be readable and /proc/sys/kernel/perf_event_paranoid == -1.</string>
</property>
<property name="text">
<string>Off-CPU Profilin&amp;g:</string>
Expand All @@ -278,7 +279,8 @@
<item row="2" column="1">
<widget class="QCheckBox" name="offCpuCheckBox">
<property name="toolTip">
<string>Record scheduler switch events. This enables off-CPU profiling to measure sleep times etc. This requires elevated privileges.</string>
<string>Record scheduler switch events. This enables off-CPU profiling to measure sleep times etc.
This requires elevated privileges or both /sys/kernel/tracing to be readable and /proc/sys/kernel/perf_event_paranoid == -1.</string>
</property>
<property name="text">
<string/>
Expand Down