Linux kernel source tree
Go to file
Michal Simek 95fee37be4 microblaze: Do loop unrolling for optimized memset implementation
Align implementation with memcpy and memmove where also remaining bytes are
copied via final switch case instead of using simple implementations which
loop. But this alignment has much stronger reason and definitely aligning
implementation is not the key point here. It is just good to have in mind
that the same technique is used already there.

In GCC 10, now -ftree-loop-distribute-patterns optimization is on at O2.
This optimization causes GCC to convert the while loop in memset.c into a
call to memset.
So this optimization is transforming a loop in a memset/memcpy into a call
to the function itself. This makes the memset implementation as recursive.
"-freestanding" option will disable the built-in library function but it
has been added in generic library implementation.

In default microblaze kernel defconfig we have CONFIG_OPT_LIB_FUNCTION
enabled so it will always pick optimized version of memset which is target
specific so we are replacing the while() loop with switch case to avoid
recursive memset call.

Issue with freestanding was already discussed in connection to commit
33d0f96ffd ("lib/string.c: Use freestanding environment") and also this
is topic in glibc and gcc.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56888
http://patchwork.ozlabs.org/project/glibc/patch/20191121021040.14554-1-sandra@codesourcery.com/

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Mahesh Bodapati <mbodapat@xilinx.com>
Link: https://lore.kernel.org/r/10a432e269a6d3349cf458e4f5792522779cba0d.1645797329.git.michal.simek@xilinx.com
2022-04-21 10:54:20 +02:00
Documentation Updates to Tracing: 2022-04-03 12:26:01 -07:00
LICENSES
arch microblaze: Do loop unrolling for optimized memset implementation 2022-04-21 10:54:20 +02:00
block for-5.18/block-2022-04-01 2022-04-01 16:20:00 -07:00
certs
crypto
drivers A single revert to fix a boot regression seen when clk_put() started 2022-04-03 12:21:14 -07:00
fs Updates to Tracing: 2022-04-03 12:26:01 -07:00
include Updates to Tracing: 2022-04-03 12:26:01 -07:00
init
ipc
kernel Updates to Tracing: 2022-04-03 12:26:01 -07:00
lib for-5.18/block-2022-04-01 2022-04-01 16:20:00 -07:00
mm Filesystem/VFS changes for 5.18, part two 2022-04-01 13:50:50 -07:00
net
samples
scripts modpost: restore the warning message for missing symbol versions 2022-04-03 03:11:51 +09:00
security
sound
tools A set of x86 fixes and updates: 2022-04-03 12:15:47 -07:00
usr
virt KVM: Remove dirty handling from gfn_to_pfn_cache completely 2022-04-02 05:34:41 -04:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap mailmap: update Kirill's email 2022-04-01 11:46:09 -07:00
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS chrome platform changes for 5.18 2022-04-02 10:44:18 -07:00
Makefile Linux 5.18-rc1 2022-04-03 14:08:21 -07:00
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.