LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Changbin Du <changbin.du@gmail.com>
To: corbet@lwn.net, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de
Cc: x86@kernel.org, linux-doc@vger.kernel.org,
	linux-kernel@vger.kernel.org, Changbin Du <changbin.du@gmail.com>,
	Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Subject: [PATCH v4 18/27] Documentation: x86: convert orc-unwinder.txt to reST
Date: Wed,  8 May 2019 23:21:32 +0800	[thread overview]
Message-ID: <20190508152141.8740-19-changbin.du@gmail.com> (raw)
In-Reply-To: <20190508152141.8740-1-changbin.du@gmail.com>

This converts the plain text documentation to reStructuredText format and
add it to Sphinx TOC tree. No essential content change.

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
---
 Documentation/x86/index.rst                   |  1 +
 .../{orc-unwinder.txt => orc-unwinder.rst}    | 27 ++++++++++---------
 2 files changed, 16 insertions(+), 12 deletions(-)
 rename Documentation/x86/{orc-unwinder.txt => orc-unwinder.rst} (93%)

diff --git a/Documentation/x86/index.rst b/Documentation/x86/index.rst
index 6e3c887a0c3b..453557097743 100644
--- a/Documentation/x86/index.rst
+++ b/Documentation/x86/index.rst
@@ -14,6 +14,7 @@ x86-specific Documentation
    kernel-stacks
    entry_64
    earlyprintk
+   orc-unwinder
    zero-page
    tlb
    mtrr
diff --git a/Documentation/x86/orc-unwinder.txt b/Documentation/x86/orc-unwinder.rst
similarity index 93%
rename from Documentation/x86/orc-unwinder.txt
rename to Documentation/x86/orc-unwinder.rst
index cd4b29be29af..d811576c1f3e 100644
--- a/Documentation/x86/orc-unwinder.txt
+++ b/Documentation/x86/orc-unwinder.rst
@@ -1,8 +1,11 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+============
 ORC unwinder
 ============
 
 Overview
---------
+========
 
 The kernel CONFIG_UNWINDER_ORC option enables the ORC unwinder, which is
 similar in concept to a DWARF unwinder.  The difference is that the
@@ -23,12 +26,12 @@ correlate instruction addresses with their stack states at run time.
 
 
 ORC vs frame pointers
----------------------
+=====================
 
 With frame pointers enabled, GCC adds instrumentation code to every
 function in the kernel.  The kernel's .text size increases by about
 3.2%, resulting in a broad kernel-wide slowdown.  Measurements by Mel
-Gorman [1] have shown a slowdown of 5-10% for some workloads.
+Gorman [1]_ have shown a slowdown of 5-10% for some workloads.
 
 In contrast, the ORC unwinder has no effect on text size or runtime
 performance, because the debuginfo is out of band.  So if you disable
@@ -55,7 +58,7 @@ depending on the kernel config.
 
 
 ORC vs DWARF
-------------
+============
 
 ORC debuginfo's advantage over DWARF itself is that it's much simpler.
 It gets rid of the complex DWARF CFI state machine and also gets rid of
@@ -65,7 +68,7 @@ mission critical oops code.
 
 The simpler debuginfo format also enables the unwinder to be much faster
 than DWARF, which is important for perf and lockdep.  In a basic
-performance test by Jiri Slaby [2], the ORC unwinder was about 20x
+performance test by Jiri Slaby [2]_, the ORC unwinder was about 20x
 faster than an out-of-tree DWARF unwinder.  (Note: That measurement was
 taken before some performance tweaks were added, which doubled
 performance, so the speedup over DWARF may be closer to 40x.)
@@ -85,7 +88,7 @@ still be able to control the format, e.g. no complex state machines.
 
 
 ORC unwind table generation
----------------------------
+===========================
 
 The ORC data is generated by objtool.  With the existing compile-time
 stack metadata validation feature, objtool already follows all code
@@ -133,7 +136,7 @@ objtool follows GCC code quite well.
 
 
 Unwinder implementation details
--------------------------------
+===============================
 
 Objtool generates the ORC data by integrating with the compile-time
 stack metadata validation feature, which is described in detail in
@@ -154,7 +157,7 @@ subset of the table needs to be searched.
 
 
 Etymology
----------
+=========
 
 Orcs, fearsome creatures of medieval folklore, are the Dwarves' natural
 enemies.  Similarly, the ORC unwinder was created in opposition to the
@@ -162,7 +165,7 @@ complexity and slowness of DWARF.
 
 "Although Orcs rarely consider multiple solutions to a problem, they do
 excel at getting things done because they are creatures of action, not
-thought." [3]  Similarly, unlike the esoteric DWARF unwinder, the
+thought." [3]_  Similarly, unlike the esoteric DWARF unwinder, the
 veracious ORC unwinder wastes no time or siloconic effort decoding
 variable-length zero-extended unsigned-integer byte-coded
 state-machine-based debug information entries.
@@ -174,6 +177,6 @@ brutal, unyielding efficiency.
 ORC stands for Oops Rewind Capability.
 
 
-[1] https://lkml.kernel.org/r/20170602104048.jkkzssljsompjdwy@suse.de
-[2] https://lkml.kernel.org/r/d2ca5435-6386-29b8-db87-7f227c2b713a@suse.cz
-[3] http://dustin.wikidot.com/half-orcs-and-orcs
+.. [1] https://lkml.kernel.org/r/20170602104048.jkkzssljsompjdwy@suse.de
+.. [2] https://lkml.kernel.org/r/d2ca5435-6386-29b8-db87-7f227c2b713a@suse.cz
+.. [3] http://dustin.wikidot.com/half-orcs-and-orcs
-- 
2.20.1


  parent reply	other threads:[~2019-05-08 15:24 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-08 15:21 [PATCH v4 00/27] Include linux x86 docs into Sphinx TOC tree Changbin Du
2019-05-08 15:21 ` [PATCH v4 01/27] Documentation: add Linux x86 docs to " Changbin Du
2019-05-08 15:21 ` [PATCH v4 02/27] Documentation: x86: convert boot.txt to reST Changbin Du
2019-05-08 15:21 ` [PATCH v4 03/27] Documentation: x86: convert topology.txt " Changbin Du
2019-05-08 15:21 ` [PATCH v4 04/27] Documentation: x86: convert exception-tables.txt " Changbin Du
2019-05-08 15:21 ` [PATCH v4 05/27] Documentation: x86: convert kernel-stacks " Changbin Du
2019-05-08 15:21 ` [PATCH v4 06/27] Documentation: x86: convert entry_64.txt " Changbin Du
2019-05-08 15:21 ` [PATCH v4 07/27] Documentation: x86: convert earlyprintk.txt " Changbin Du
2019-05-08 15:21 ` [PATCH v4 08/27] Documentation: x86: convert zero-page.txt " Changbin Du
2019-05-08 15:21 ` [PATCH v4 09/27] Documentation: x86: convert tlb.txt " Changbin Du
2019-05-08 15:21 ` [PATCH v4 10/27] Documentation: x86: convert mtrr.txt " Changbin Du
2019-05-08 15:21 ` [PATCH v4 11/27] Documentation: x86: convert pat.txt " Changbin Du
2019-05-08 15:21 ` [PATCH v4 12/27] Documentation: x86: convert protection-keys.txt " Changbin Du
2019-05-08 15:21 ` [PATCH v4 13/27] Documentation: x86: convert intel_mpx.txt " Changbin Du
2019-05-08 15:21 ` [PATCH v4 14/27] Documentation: x86: convert amd-memory-encryption.txt " Changbin Du
2019-05-08 15:21 ` [PATCH v4 15/27] Documentation: x86: convert pti.txt " Changbin Du
2019-05-08 15:21 ` [PATCH v4 16/27] Documentation: x86: convert microcode.txt " Changbin Du
2019-05-08 15:21 ` [PATCH v4 17/27] Documentation: x86: convert resctrl_ui.txt " Changbin Du
2019-05-08 15:21 ` Changbin Du [this message]
2019-05-08 15:21 ` [PATCH v4 19/27] Documentation: x86: convert usb-legacy-support.txt " Changbin Du
2019-05-08 15:21 ` [PATCH v4 20/27] Documentation: x86: convert i386/IO-APIC.txt " Changbin Du
2019-05-08 15:21 ` [PATCH v4 21/27] Documentation: x86: convert x86_64/boot-options.txt " Changbin Du
2019-05-08 15:21 ` [PATCH v4 22/27] Documentation: x86: convert x86_64/uefi.txt " Changbin Du
2019-05-08 15:21 ` [PATCH v4 23/27] Documentation: x86: convert x86_64/mm.txt " Changbin Du
2019-05-08 15:21 ` [PATCH v4 24/27] Documentation: x86: convert x86_64/5level-paging.txt " Changbin Du
2019-05-08 15:21 ` [PATCH v4 25/27] Documentation: x86: convert x86_64/fake-numa-for-cpusets " Changbin Du
2019-05-08 15:21 ` [PATCH v4 26/27] Documentation: x86: convert x86_64/cpu-hotplug-spec " Changbin Du
2019-05-08 15:21 ` [PATCH v4 27/27] Documentation: x86: convert x86_64/machinecheck " Changbin Du
2019-05-08 20:40 ` [PATCH v4 00/27] Include linux x86 docs into Sphinx TOC tree Jonathan Corbet

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190508152141.8740-19-changbin.du@gmail.com \
    --to=changbin.du@gmail.com \
    --cc=bp@alien8.de \
    --cc=corbet@lwn.net \
    --cc=linux-doc@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mchehab+samsung@kernel.org \
    --cc=mingo@redhat.com \
    --cc=tglx@linutronix.de \
    --cc=x86@kernel.org \
    --subject='Re: [PATCH v4 18/27] Documentation: x86: convert orc-unwinder.txt to reST' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).