Kernel Source and devicetree for NOTHING Phone(3a) and Phone(3a)Pro
5e21f2d577
A get_random_bytes() function can cause a high contention if it is called across CPUs simultaneously. Because it shares one lock per all CPUs: <snip> class name con-bounces contentions waittime-min waittime-max waittime-total waittime-avg acq-bounces acquisitions holdtime-min holdtime-max holdtime-total holdtime-avg &crng->lock: 663145 665886 0.05 8.85 261966.66 0.39 7188152 13731279 0.04 11.89 2181582.30 0.16 ----------- &crng->lock 307835 [<00000000acba59cd>] _extract_crng+0x48/0x90 &crng->lock 358051 [<00000000f0075abc>] _crng_backtrack_protect+0x32/0x90 ----------- &crng->lock 234241 [<00000000f0075abc>] _crng_backtrack_protect+0x32/0x90 &crng->lock 431645 [<00000000acba59cd>] _extract_crng+0x48/0x90 <snip> Switch from the get_random_bytes() to prandom_u32() that does not have any internal contention when a random value is needed for the tests. The reason is to minimize CPU cycles introduced by the test-suite itself from the vmalloc performance metrics. Link: https://lkml.kernel.org/r/20220607093449.3100-6-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| 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 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.