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Diffstat (limited to 'Documentation/RCU/Design')
| -rw-r--r-- | Documentation/RCU/Design/Data-Structures/Data-Structures.html | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/Documentation/RCU/Design/Data-Structures/Data-Structures.html b/Documentation/RCU/Design/Data-Structures/Data-Structures.html index e4bf20a68fa3..4dec89097559 100644 --- a/Documentation/RCU/Design/Data-Structures/Data-Structures.html +++ b/Documentation/RCU/Design/Data-Structures/Data-Structures.html @@ -1106,6 +1106,7 @@ Its fields are as follows: 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>->dynticks_nesting</tt> field counts the @@ -1131,12 +1132,20 @@ 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>Finally the <tt>->rcu_qs_ctr</tt> field is used to record +</p><p>The <tt>->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>->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>->rcu_qs_ctr</tt> +in response. + <table> <tr><th> </th></tr> <tr><th align="left">Quick Quiz:</th></tr> |