lkml.org 
[lkml]   [2022]   [Mar]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Subject[PATCH v1 0/4] Kill the time spent in patch_instruction()
Date
This series reduces by 70% the time required to activate
ftrace on an 8xx with CONFIG_STRICT_KERNEL_RWX.

Measure is performed in function ftrace_replace_code() using mftb()
around the loop.

With the series,
- Without CONFIG_STRICT_KERNEL_RWX, 416000 TB ticks are measured.
- With CONFIG_STRICT_KERNEL_RWX, 546000 TB ticks are measured.

Before this series,
- Without CONFIG_STRICT_KERNEL_RWX, 427000 TB ticks are measured.
- With CONFIG_STRICT_KERNEL_RWX, 1744000 TB ticks are measured.

Before the series, CONFIG_STRICT_KERNEL_RWX multiplies the time
required for ftrace activation by more than 4.

With the series, CONFIG_STRICT_KERNEL_RWX increases the time
required for ftrace activation by only 30%

Christophe Leroy (4):
powerpc/code-patching: Don't call is_vmalloc_or_module_addr() without
CONFIG_MODULES
powerpc/code-patching: Speed up page mapping/unmapping
powerpc/code-patching: Use jump_label for testing freed initmem
powerpc/code-patching: Use jump_label to check if poking_init() is
done

arch/powerpc/include/asm/code-patching.h | 2 ++
arch/powerpc/lib/code-patching.c | 37 +++++++++++++++---------
arch/powerpc/mm/mem.c | 2 ++
3 files changed, 28 insertions(+), 13 deletions(-)

--
2.35.1

\
 
 \ /
  Last update: 2022-03-22 16:41    [W:0.167 / U:0.088 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site