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author | Linus Torvalds <torvalds@linux-foundation.org> | 2024-11-16 08:12:43 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2024-11-16 08:12:43 -0800 |
commit | b5a24181e461e8bfa8cdf35e1804679dc1bebcdd (patch) | |
tree | f45b614132f0454cf37cf36a9fe496c598ef9242 /drivers/iio/temperature/tsys02d.c | |
parent | e8bdb3c8be08c9a3edc0a373c0aa8729355a0705 (diff) | |
parent | 09663753bb7c50b33f8e5fa562c20ce275b88237 (diff) | |
download | linux-master.tar.gz linux-master.tar.bz2 linux-master.zip |
Merge tag 'trace-ringbuffer-v6.12-rc7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-traceHEADmaster
Pull ring buffer fixes from Steven Rostedt:
- Revert: "ring-buffer: Do not have boot mapped buffers hook to CPU
hotplug"
A crash that happened on cpu hotplug was actually caused by the
incorrect ref counting that was fixed by commit 2cf9733891a4
("ring-buffer: Fix refcount setting of boot mapped buffers"). The
removal of calling cpu hotplug callbacks on memory mapped buffers was
not an issue even though the tests at the time pointed toward it. But
in fact, there's a check in that code that tests to see if the
buffers are already allocated or not, and will not allocate them
again if they are. Not calling the cpu hotplug callbacks ended up not
initializing the non boot CPU buffers.
Simply remove that change.
- Clear all CPU buffers when starting tracing in a boot mapped buffer
To properly process events from a previous boot, the address space
needs to be accounted for due to KASLR and the events in the buffer
are updated accordingly when read. This also requires that when the
buffer has tracing enabled again in the current boot that the buffers
are reset so that events from the previous boot do not interact with
the events of the current boot and cause confusing due to not having
the proper meta data.
It was found that if a CPU is taken offline, that its per CPU buffer
is not reset when tracing starts. This allows for events to be from
both the previous boot and the current boot to be in the buffer at
the same time. Clear all CPU buffers when tracing is started in a
boot mapped buffer.
* tag 'trace-ringbuffer-v6.12-rc7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing/ring-buffer: Clear all memory mapped CPU ring buffers on first recording
Revert: "ring-buffer: Do not have boot mapped buffers hook to CPU hotplug"
Diffstat (limited to 'drivers/iio/temperature/tsys02d.c')
0 files changed, 0 insertions, 0 deletions