Mathieu Desnoyers
98bf0fbb65
Remove conditional locking by moving the __DO_TRACE() code into trace_##name(). When the faultable syscall tracepoints were implemented, __DO_TRACE() had a rcuidle argument which selected between SRCU and preempt disable. Therefore, the RCU tasks trace protection for faultable syscall tracepoints was introduced using the same pattern. At that point, it did not appear obvious that this feedback from Linus [1] applied here as well, because the __DO_TRACE() modification was extending a pre-existing pattern. Shortly before pulling the faultable syscall tracepoints modifications, Steven removed the rcuidle argument and SRCU protection scheme entirely from tracepoint.h: commit48bcda6848("tracing: Remove definition of trace_*_rcuidle()") This required a rebase of the faultable syscall tracepoints series, which missed a perfect opportunity to integrate the prior recommendation from Linus. In response to the pull request, Linus pointed out [2] that he was not pleased by the implementation, expecting this to be fixed in a follow up patch series. Move __DO_TRACE() code into trace_##name() within each of __DECLARE_TRACE() and __DECLARE_TRACE_SYSCALL(). Use a scoped guard to guard the preempt disable notrace and RCU tasks trace critical sections. Link: https://lore.kernel.org/all/CAHk-=wggDLDeTKbhb5hh--x=-DQd69v41137M72m6NOTmbD-cw@mail.gmail.com/ [1] Link: https://lore.kernel.org/lkml/CAHk-=witPrLcu22dZ93VCyRQonS7+-dFYhQbna=KBa-TAhayMw@mail.gmail.com/ [2] Fixes:a363d27cdb("tracing: Allow system call tracepoints to handle page faults") Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Michael Jeanson <mjeanson@efficios.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Yonghong Song <yhs@fb.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com> Cc: bpf@vger.kernel.org Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Jordan Rife <jrife@google.com> Cc: linux-trace-kernel@vger.kernel.org Link: https://lore.kernel.org/20241123153031.2884933-5-mathieu.desnoyers@efficios.com Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.