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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-18 17:39:57 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-18 17:39:57 +0000
commitdc50eab76b709d68175a358d6e23a5a3890764d3 (patch)
treec754d0390db060af0213ff994f0ac310e4cfd6e9 /Documentation/RCU
parentAdding debian version 6.6.15-2. (diff)
downloadlinux-dc50eab76b709d68175a358d6e23a5a3890764d3.tar.xz
linux-dc50eab76b709d68175a358d6e23a5a3890764d3.zip
Merging upstream version 6.7.7.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'Documentation/RCU')
-rw-r--r--Documentation/RCU/Design/Expedited-Grace-Periods/Expedited-Grace-Periods.rst2
-rw-r--r--Documentation/RCU/Design/Memory-Ordering/TreeRCU-callback-registry.svg9
-rw-r--r--Documentation/RCU/Design/Memory-Ordering/TreeRCU-gp-fqs.svg4
-rw-r--r--Documentation/RCU/Design/Memory-Ordering/TreeRCU-gp.svg13
-rw-r--r--Documentation/RCU/Design/Memory-Ordering/TreeRCU-hotplug.svg4
-rw-r--r--Documentation/RCU/Design/Requirements/Requirements.rst4
-rw-r--r--Documentation/RCU/listRCU.rst9
-rw-r--r--Documentation/RCU/whatisRCU.rst4
8 files changed, 20 insertions, 29 deletions
diff --git a/Documentation/RCU/Design/Expedited-Grace-Periods/Expedited-Grace-Periods.rst b/Documentation/RCU/Design/Expedited-Grace-Periods/Expedited-Grace-Periods.rst
index 93d899d532..414f8a2012 100644
--- a/Documentation/RCU/Design/Expedited-Grace-Periods/Expedited-Grace-Periods.rst
+++ b/Documentation/RCU/Design/Expedited-Grace-Periods/Expedited-Grace-Periods.rst
@@ -181,7 +181,7 @@ operations is carried out at several levels:
of this wait (or series of waits, as the case may be) is to permit a
concurrent CPU-hotplug operation to complete.
#. In the case of RCU-sched, one of the last acts of an outgoing CPU is
- to invoke ``rcu_report_dead()``, which reports a quiescent state for
+ to invoke ``rcutree_report_cpu_dead()``, which reports a quiescent state for
that CPU. However, this is likely paranoia-induced redundancy.
+-----------------------------------------------------------------------+
diff --git a/Documentation/RCU/Design/Memory-Ordering/TreeRCU-callback-registry.svg b/Documentation/RCU/Design/Memory-Ordering/TreeRCU-callback-registry.svg
index 7ac6f92698..63eff86717 100644
--- a/Documentation/RCU/Design/Memory-Ordering/TreeRCU-callback-registry.svg
+++ b/Documentation/RCU/Design/Memory-Ordering/TreeRCU-callback-registry.svg
@@ -566,15 +566,6 @@
style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier">rcutree_migrate_callbacks()</text>
<text
xml:space="preserve"
- x="8335.4873"
- y="5357.1006"
- font-style="normal"
- font-weight="bold"
- font-size="192"
- id="text202-7-9-6-0"
- style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier">rcu_migrate_callbacks()</text>
- <text
- xml:space="preserve"
x="8768.4678"
y="6224.9038"
font-style="normal"
diff --git a/Documentation/RCU/Design/Memory-Ordering/TreeRCU-gp-fqs.svg b/Documentation/RCU/Design/Memory-Ordering/TreeRCU-gp-fqs.svg
index 7ddc094d7f..d82a77d03d 100644
--- a/Documentation/RCU/Design/Memory-Ordering/TreeRCU-gp-fqs.svg
+++ b/Documentation/RCU/Design/Memory-Ordering/TreeRCU-gp-fqs.svg
@@ -1135,7 +1135,7 @@
font-weight="bold"
font-size="192"
id="text202-7-5-3-27-6-5"
- style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier">rcu_report_dead()</text>
+ style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier">rcutree_report_cpu_dead()</text>
<text
xml:space="preserve"
x="3745.7725"
@@ -1256,7 +1256,7 @@
font-style="normal"
y="3679.27"
x="-3804.9949"
- xml:space="preserve">rcu_cpu_starting()</text>
+ xml:space="preserve">rcutree_report_cpu_starting()</text>
<g
style="fill:none;stroke-width:0.025in"
id="g3107-7-5-0"
diff --git a/Documentation/RCU/Design/Memory-Ordering/TreeRCU-gp.svg b/Documentation/RCU/Design/Memory-Ordering/TreeRCU-gp.svg
index 069f6f8371..53e0dc2a2c 100644
--- a/Documentation/RCU/Design/Memory-Ordering/TreeRCU-gp.svg
+++ b/Documentation/RCU/Design/Memory-Ordering/TreeRCU-gp.svg
@@ -1448,15 +1448,6 @@
style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier">rcutree_migrate_callbacks()</text>
<text
xml:space="preserve"
- x="8335.4873"
- y="5357.1006"
- font-style="normal"
- font-weight="bold"
- font-size="192"
- id="text202-7-9-6-0"
- style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier">rcu_migrate_callbacks()</text>
- <text
- xml:space="preserve"
x="8768.4678"
y="6224.9038"
font-style="normal"
@@ -3274,7 +3265,7 @@
font-weight="bold"
font-size="192"
id="text202-7-5-3-27-6-5"
- style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier">rcu_report_dead()</text>
+ style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier">rcutree_report_cpu_dead()</text>
<text
xml:space="preserve"
x="3745.7725"
@@ -3395,7 +3386,7 @@
font-style="normal"
y="3679.27"
x="-3804.9949"
- xml:space="preserve">rcu_cpu_starting()</text>
+ xml:space="preserve">rcutree_report_cpu_starting()</text>
<g
style="fill:none;stroke-width:0.025in"
id="g3107-7-5-0"
diff --git a/Documentation/RCU/Design/Memory-Ordering/TreeRCU-hotplug.svg b/Documentation/RCU/Design/Memory-Ordering/TreeRCU-hotplug.svg
index 2c9310ba29..4fa7506082 100644
--- a/Documentation/RCU/Design/Memory-Ordering/TreeRCU-hotplug.svg
+++ b/Documentation/RCU/Design/Memory-Ordering/TreeRCU-hotplug.svg
@@ -607,7 +607,7 @@
font-weight="bold"
font-size="192"
id="text202-7-5-3-27-6"
- style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier">rcu_report_dead()</text>
+ style="font-size:192px;font-style:normal;font-weight:bold;text-anchor:start;fill:#000000;stroke-width:0.025in;font-family:Courier">rcutree_report_cpu_dead()</text>
<text
xml:space="preserve"
x="3745.7725"
@@ -728,7 +728,7 @@
font-style="normal"
y="3679.27"
x="-3804.9949"
- xml:space="preserve">rcu_cpu_starting()</text>
+ xml:space="preserve">rcutree_report_cpu_starting()</text>
<g
style="fill:none;stroke-width:0.025in"
id="g3107-7-5-0"
diff --git a/Documentation/RCU/Design/Requirements/Requirements.rst b/Documentation/RCU/Design/Requirements/Requirements.rst
index f3b605285a..cccafdaa1f 100644
--- a/Documentation/RCU/Design/Requirements/Requirements.rst
+++ b/Documentation/RCU/Design/Requirements/Requirements.rst
@@ -1955,12 +1955,12 @@ if offline CPUs block an RCU grace period for too long.
An offline CPU's quiescent state will be reported either:
-1. As the CPU goes offline using RCU's hotplug notifier (rcu_report_dead()).
+1. As the CPU goes offline using RCU's hotplug notifier (rcutree_report_cpu_dead()).
2. When grace period initialization (rcu_gp_init()) detects a
race either with CPU offlining or with a task unblocking on a leaf
``rcu_node`` structure whose CPUs are all offline.
-The CPU-online path (rcu_cpu_starting()) should never need to report
+The CPU-online path (rcutree_report_cpu_starting()) should never need to report
a quiescent state for an offline CPU. However, as a debugging measure,
it does emit a warning if a quiescent state was not already reported
for that CPU.
diff --git a/Documentation/RCU/listRCU.rst b/Documentation/RCU/listRCU.rst
index bdc4bcc528..ed5c9d8c9a 100644
--- a/Documentation/RCU/listRCU.rst
+++ b/Documentation/RCU/listRCU.rst
@@ -8,6 +8,15 @@ One of the most common uses of RCU is protecting read-mostly linked lists
that all of the required memory ordering is provided by the list macros.
This document describes several list-based RCU use cases.
+When iterating a list while holding the rcu_read_lock(), writers may
+modify the list. The reader is guaranteed to see all of the elements
+which were added to the list before they acquired the rcu_read_lock()
+and are still on the list when they drop the rcu_read_unlock().
+Elements which are added to, or removed from the list may or may not
+be seen. If the writer calls list_replace_rcu(), the reader may see
+either the old element or the new element; they will not see both,
+nor will they see neither.
+
Example 1: Read-mostly list: Deferred Destruction
-------------------------------------------------
diff --git a/Documentation/RCU/whatisRCU.rst b/Documentation/RCU/whatisRCU.rst
index e488c8e557..60ce024751 100644
--- a/Documentation/RCU/whatisRCU.rst
+++ b/Documentation/RCU/whatisRCU.rst
@@ -59,8 +59,8 @@ experiment with should focus on Section 2. People who prefer to start
with example uses should focus on Sections 3 and 4. People who need to
understand the RCU implementation should focus on Section 5, then dive
into the kernel source code. People who reason best by analogy should
-focus on Section 6. Section 7 serves as an index to the docbook API
-documentation, and Section 8 is the traditional answer key.
+focus on Section 6 and 7. Section 8 serves as an index to the docbook
+API documentation, and Section 9 is the traditional answer key.
So, start with the section that makes the most sense to you and your
preferred method of learning. If you need to know everything about