samsung_sm8750/android_kernel_samsung_sm8750
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Merge branches 'doc.2017.04.12a', 'fixes.2017.04.19a' and 'srcu.2017.04.21a' into HEAD

Browse Source 
doc.2017.04.12a: Documentation updates
fixes.2017.04.19a: Miscellaneous fixes
srcu.2017.04.21a: Parallelize SRCU callback handling
This commit is contained in:
Paul E. McKenney
2017-04-21 06:00:13 -07:00
parent b26cfc48e3 bfd090be14 bcbfdd01dc
commit f2094107ac
65 changed files with 3173 additions and 867 deletions
Download Patch File Download Diff File Expand all files Collapse all files

26
Documentation/RCU/Design/Data-Structures/Data-Structures.html
View File

@@ -1185,6 +1185,9 @@ Its fields are as follows:
1 int dynticks_nesting;
2 int dynticks_nmi_nesting;
3 atomic_t dynticks;
4 bool rcu_need_heavy_qs;
5 unsigned long rcu_qs_ctr;
6 bool rcu_urgent_qs;
</pre>
<p>The <tt>-&gt;dynticks_nesting</tt> field counts the
@@ -1198,11 +1201,32 @@ NMIs are counted by the <tt>-&gt;dynticks_nmi_nesting</tt>
field, except that NMIs that interrupt non-dyntick-idle execution
are not counted.
</p><p>Finally, the <tt>-&gt;dynticks</tt> field counts the corresponding
</p><p>The <tt>-&gt;dynticks</tt> field counts the corresponding
CPU's transitions to and from dyntick-idle mode, so that this counter
has an even value when the CPU is in dyntick-idle mode and an odd
value otherwise.
</p><p>The <tt>-&gt;rcu_need_heavy_qs</tt> field is used
to record the fact that the RCU core code would really like to
see a quiescent state from the corresponding CPU, so much so that
it is willing to call for heavy-weight dyntick-counter operations.
This flag is checked by RCU's context-switch and <tt>cond_resched()</tt>
code, which provide a momentary idle sojourn in response.
</p><p>The <tt>-&gt;rcu_qs_ctr</tt> field is used to record
quiescent states from <tt>cond_resched()</tt>.
Because <tt>cond_resched()</tt> can execute quite frequently, this
must be quite lightweight, as in a non-atomic increment of this
per-CPU field.
</p><p>Finally, the <tt>-&gt;rcu_urgent_qs</tt> field is used to record
the fact that the RCU core code would really like to see a quiescent
state from the corresponding CPU, with the various other fields indicating
just how badly RCU wants this quiescent state.
This flag is checked by RCU's context-switch and <tt>cond_resched()</tt>
code, which, if nothing else, non-atomically increment <tt>-&gt;rcu_qs_ctr</tt>
in response.
<table>
<tr><th>&nbsp;</th></tr>
<tr><th align="left">Quick Quiz:</th></tr>