mirror of
https://github.com/torvalds/linux.git
synced 2025-11-02 01:29:02 +02:00
Linux kernel source tree
2accfdb7ef
This is the really old legacy kernel profiling code, which has long since been obviated by "real profiling" (ie 'prof' and company), and mainly remains as a source of syzbot reports. There are anecdotal reports that people still use it for boot-time profiling, but it's unlikely that such use would care about the old NUMA optimizations in this code from 2004 (commit ad02973d42: "profile: 512x Altix timer interrupt livelock fix" in the BK import archive at [1]) So in order to head off future syzbot reports, let's try to simplify this code and get rid of the per-cpu profile buffers that are quite a large portion of the complexity footprint of this thing (including CPU hotplug callbacks etc). It's unlikely anybody will actually notice, or possibly, as Thomas put it: "Only people who indulge in nostalgia will notice :)". That said, if it turns out that this code is actually actively used by somebody, we can always revert this removal. Thus the "attempt" in the summary line. [ Note: in a small nod to "the profiling code can cause NUMA problems", this also removes the "increment the last entry in the profiling array on any unknown hits" logic. That would account any program counter in a module to that single counter location, and might exacerbate any NUMA cacheline bouncing issues ] Link: https://lore.kernel.org/all/CAHk-=wgs52BxT4Zjmjz8aNvHWKxf5_ThBY4bYL1Y6CTaNL2dTw@mail.gmail.com/ Link: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git [1] Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .editorconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .rustfmt.toml | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| 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 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.