40769665b6
Currently the 'MetricExpr' json value is passed from the json file to the pmu-events.c. This change introduces an expression tree that is parsed into. The parsing is done largely by using operator overloading and python's 'eval' function. Two advantages in doing this are: 1) Broken metrics fail at compile time rather than relying on `perf test` to detect. `perf test` remains relevant for checking event encoding and actual metric use. 2) The conversion to a string from the tree can minimize the metric's string size, for example, preferring 1e6 over 1000000, avoiding multiplication by 1 and removing unnecessary whitespace. On x86 this reduces the string size by 2,930bytes (0.07%). In future changes it would be possible to programmatically generate the json expressions (a single line of text and so a pain to write manually) for an architecture using the expression tree. This could avoid copy-pasting metrics for all architecture variants. v4. Doesn't simplify "0*SLOTS" to 0, as the pattern is used to fix Intel metrics with topdown events. v3. Avoids generic types on standard types like set that aren't supported until Python 3.9, fixing an issue with Python 3.6 reported-by John Garry. v3 also fixes minor pylint issues and adds a call to Simplify on the read expression tree. v2. Improvements to type information. Committer notes: Added one-line fixer from Ian, see first Link: tag below. Signed-off-by: Ian Rogers <irogers@google.com> Reviewed-by: John Garry <john.g.garry@oracle.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Thomas Richter <tmricht@linux.ibm.com> Link: https://lore.kernel.org/r/CAP-5=fWa=zNK_ecpWGoGggHCQx7z-oW0eGMQf19Maywg0QK=4g@mail.gmail.com Link: https://lore.kernel.org/r/20221207055908.1385448-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
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Documentation | ||
LICENSES | ||
arch | ||
block | ||
certs | ||
crypto | ||
drivers | ||
fs | ||
include | ||
init | ||
io_uring | ||
ipc | ||
kernel | ||
lib | ||
mm | ||
net | ||
rust | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
virt | ||
.clang-format | ||
.cocciconfig | ||
.get_maintainer.ignore | ||
.gitattributes | ||
.gitignore | ||
.mailmap | ||
.rustfmt.toml | ||
COPYING | ||
CREDITS | ||
Kbuild | ||
Kconfig | ||
MAINTAINERS | ||
Makefile | ||
README |
README
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 Restructured Text 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.