From: Peter Oberparleiter <oberpar@linux.ibm.com>
To: Sasha Levin <sashal@kernel.org>, linux-kernel@vger.kernel.org
Cc: Adrian Hunter <adrian.hunter@intel.com>,
Alexander Potapenko <glider@google.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Andrew Morton <akpm@linux-foundation.org>,
Andrey Konovalov <andreyknvl@gmail.com>,
Andy Lutomirski <luto@kernel.org>,
Anton Ivanov <anton.ivanov@cambridgegreys.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Arnd Bergmann <arnd@arndb.de>, Ben Segall <bsegall@google.com>,
Bill Wendling <morbo@google.com>, Boqun Feng <boqun@kernel.org>,
Borislav Petkov <bp@alien8.de>, Chuck Wolber <chuck@wolber.net>,
Dave Hansen <dave.hansen@linux.intel.com>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Dmitry Vyukov <dvyukov@google.com>,
Frantisek Hrbata <fhrbata@redhat.com>,
Frederic Weisbecker <frederic@kernel.org>,
"H. Peter Anvin" <hpa@zytor.com>, Ian Rogers <irogers@google.com>,
Ingo Molnar <mingo@redhat.com>,
James Clark <james.clark@linaro.org>,
Jiri Olsa <jolsa@kernel.org>,
Johannes Berg <johannes@sipsolutions.net>,
Jonathan Corbet <corbet@lwn.net>,
Josh Poimboeuf <jpoimboe@kernel.org>,
Julian Braha <julianbraha@gmail.com>,
Juri Lelli <juri.lelli@redhat.com>,
Justin Stitt <justinstitt@google.com>,
kasan-dev@googlegroups.com,
K Prateek Nayak <kprateek.nayak@amd.com>,
linux-doc@vger.kernel.org, linux-kbuild@vger.kernel.org,
llvm@lists.linux.dev, Marco Elver <elver@google.com>,
Mark Rutland <mark.rutland@arm.com>,
Masami Hiramatsu <mhiramat@kernel.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Mauro Carvalho Chehab <mchehab@kernel.org>,
Mel Gorman <mgorman@suse.de>, Miguel Ojeda <ojeda@kernel.org>,
Namhyung Kim <namhyung@kernel.org>,
Nathan Chancellor <nathan@kernel.org>,
Nick Desaulniers <ndesaulniers@google.com>,
Nicolas Schier <nsc@kernel.org>,
Paolo Bonzini <pbonzini@redhat.com>,
"Paul E. McKenney" <paulmck@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Randy Dunlap <rdunlap@infradead.org>,
Richard Weinberger <richard@nod.at>,
Sean Christopherson <seanjc@google.com>,
Shuah Khan <skhan@linuxfoundation.org>,
Steven Rostedt <rostedt@goodmis.org>,
Thomas Gleixner <tglx@kernel.org>,
Valentin Schneider <vschneid@redhat.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Waiman Long <longman@redhat.com>, Will Deacon <will@kernel.org>,
x86@kernel.org, Konstantin Khorenko <khorenko@virtuozzo.com>
Subject: Re: [PATCH v2 00/20] Unify code coverage and add Clang source-based coverage with MC/DC
Date: Thu, 5 Nov 2026 18:36:14 +0100 [thread overview]
Message-ID: <fbfb36b4-1ac7-444b-b898-f509f0b3c273@linux.ibm.com> (raw)
In-Reply-To: <20261103015238.3780910-1-sashal@kernel.org>
On 03.11.2026 02:52, Sasha Levin wrote:
> The previous postings of Clang's source-based code coverage [1][2] drew
> objections [3][4]: rather than a third coverage implementation with its
> own interface next to gcov and KCOV, reviewers asked for a unified
> coverage interface, and for coverage instrumentation to honour noinstr.
> This series first restructures the existing coverage support into one
> framework, then adds source-based coverage and MC/DC as part of it.
Thanks for driving these improvements to the kernel coverage
infrastructure! The overall approach taken to unify the different
backends looks sane to me, and I'm looking forward to seeing this
integrated!
I successfully tested the gcov-backend on s390 with GCC 16.1.0, GCC
15.2.0 and latest Clang 24 (git).
[...]
> - Runtime interface: /sys/kernel/debug/coverage/, with "backend" naming
> the backend and its features, "reset" resetting its data, and the
> backend's data files. The existing gcov and kcov entries stay where
> they are, for lcov and syzkaller, and are linked from there.
Just as a FYI - I found a minor incompatibility when using lcov with the
series applied where it fails to automatically determine the kernel base
directory due to the changed location of gcov-kernel base code, but
that's nothing that should affect the kernel series. The issue can be
worked around by specifying the path manually and I'm planning to
address this with a corresponding lcov change once the series is integrated.
--
Peter Oberparleiter
Linux on IBM Z Development - IBM Germany R&D
prev parent reply other threads:[~2026-11-05 17:37 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-11-03 1:52 Sasha Levin
2026-11-03 1:52 ` [PATCH v2 01/20] coverage: move gcov and kcov under kernel/coverage/ Sasha Levin
2026-11-05 17:38 ` Peter Oberparleiter
2026-11-03 1:52 ` [PATCH v2 02/20] kbuild: unify static coverage instrumentation as COVERAGE_PROFILE Sasha Levin
2026-11-03 1:52 ` [PATCH v2 03/20] coverage: add a common debugfs interface Sasha Levin
2026-11-05 17:49 ` Peter Oberparleiter
2026-11-06 1:05 ` Sasha Levin
2026-11-03 1:52 ` [PATCH v2 04/20] compiler_types.h: Don't instrument __always_inline functions for coverage Sasha Levin
2026-11-03 1:52 ` [PATCH v2 05/20] context_tracking: Always inline the empty stubs called from noinstr code Sasha Levin
2026-11-03 1:52 ` [PATCH v2 06/20] lockdep: " Sasha Levin
2026-11-03 1:52 ` [PATCH v2 07/20] perf: Always inline the empty perf_lopwr_cb() stub Sasha Levin
2026-11-03 1:52 ` [PATCH v2 08/20] rseq: Always inline the empty stubs called from noinstr code Sasha Levin
2026-11-03 1:52 ` [PATCH v2 09/20] x86: Always inline " Sasha Levin
2026-11-03 1:52 ` [PATCH v2 10/20] x86/sev: Use non-instrumented bitops in the GHCB accessors Sasha Levin
2026-11-04 13:36 ` Sean Christopherson
2026-11-03 1:52 ` [PATCH v2 11/20] objtool: Detect code coverage instrumentation in noinstr code Sasha Levin
2026-11-03 1:52 ` [PATCH v2 12/20] x86/sev: Stop excluding noinstr.o from code coverage Sasha Levin
2026-11-03 1:52 ` [PATCH v2 13/20] x86/entry: Stop excluding the entry code from KCOV Sasha Levin
2026-11-03 1:52 ` [PATCH v2 14/20] coverage: add Clang's source-based code coverage Sasha Levin
2026-11-03 1:52 ` [PATCH v2 15/20] x86: Enable " Sasha Levin
2026-11-03 1:52 ` [PATCH v2 16/20] coverage: add MC/DC measurement Sasha Levin
2026-11-03 1:52 ` [PATCH v2 17/20] gcov: fix gcov_info_add() merge semantics for IOR counters Sasha Levin
2026-11-05 17:50 ` Peter Oberparleiter
2026-11-03 1:52 ` [PATCH v2 18/20] kconfig: add CC_HAS_CONDITION_COVERAGE for MC/DC support detection Sasha Levin
2026-11-03 1:52 ` [PATCH v2 19/20] gcov: add MC/DC condition coverage support Sasha Levin
2026-11-05 17:56 ` Peter Oberparleiter
2026-11-06 1:05 ` Sasha Levin
2026-11-03 1:52 ` [PATCH v2 20/20] Documentation: dev-tools: document the common code coverage interface Sasha Levin
2026-11-05 17:36 ` Peter Oberparleiter [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=fbfb36b4-1ac7-444b-b898-f509f0b3c273@linux.ibm.com \
--to=oberpar@linux.ibm.com \
--cc=acme@kernel.org \
--cc=adrian.hunter@intel.com \
--cc=akpm@linux-foundation.org \
--cc=alexander.shishkin@linux.intel.com \
--cc=andreyknvl@gmail.com \
--cc=anton.ivanov@cambridgegreys.com \
--cc=arnd@arndb.de \
--cc=boqun@kernel.org \
--cc=bp@alien8.de \
--cc=bsegall@google.com \
--cc=chuck@wolber.net \
--cc=corbet@lwn.net \
--cc=dave.hansen@linux.intel.com \
--cc=dietmar.eggemann@arm.com \
--cc=dvyukov@google.com \
--cc=elver@google.com \
--cc=fhrbata@redhat.com \
--cc=frederic@kernel.org \
--cc=glider@google.com \
--cc=hpa@zytor.com \
--cc=irogers@google.com \
--cc=james.clark@linaro.org \
--cc=johannes@sipsolutions.net \
--cc=jolsa@kernel.org \
--cc=jpoimboe@kernel.org \
--cc=julianbraha@gmail.com \
--cc=juri.lelli@redhat.com \
--cc=justinstitt@google.com \
--cc=kasan-dev@googlegroups.com \
--cc=khorenko@virtuozzo.com \
--cc=kprateek.nayak@amd.com \
--cc=linux-doc@vger.kernel.org \
--cc=linux-kbuild@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=llvm@lists.linux.dev \
--cc=longman@redhat.com \
--cc=luto@kernel.org \
--cc=mark.rutland@arm.com \
--cc=mathieu.desnoyers@efficios.com \
--cc=mchehab@kernel.org \
--cc=mgorman@suse.de \
--cc=mhiramat@kernel.org \
--cc=mingo@redhat.com \
--cc=morbo@google.com \
--cc=namhyung@kernel.org \
--cc=nathan@kernel.org \
--cc=ndesaulniers@google.com \
--cc=nsc@kernel.org \
--cc=ojeda@kernel.org \
--cc=paulmck@kernel.org \
--cc=pbonzini@redhat.com \
--cc=peterz@infradead.org \
--cc=rdunlap@infradead.org \
--cc=richard@nod.at \
--cc=rostedt@goodmis.org \
--cc=sashal@kernel.org \
--cc=seanjc@google.com \
--cc=skhan@linuxfoundation.org \
--cc=tglx@kernel.org \
--cc=vincent.guittot@linaro.org \
--cc=vschneid@redhat.com \
--cc=will@kernel.org \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®