| Date | Tue, 16 Apr 2019 09:50:38 -0700 | From | Davidlohr Bueso <> | Subject | Re: [PATCH v4 10/16] locking/rwsem: Wake up almost all readers in wait queue |
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On Sat, 13 Apr 2019, Waiman Long wrote: >+/* >+ * We limit the maximum number of readers that can be woken up for a >+ * wake-up call to not penalizing the waking thread for spending too >+ * much time doing it. >+ */ >+#define MAX_READERS_WAKEUP 0x100
Although with wake_q this is not really so... Could it at least be rewritten, dunno something like so:
/* * Magic number to batch-wakeup waiting readers, even when writers * are also present in the queue. This both limits the amount of * work the waking thread must do (albeit wake_q) and also prevents * any potential counter overflow, however unlikely. */
I'm still not crazy about this artificial limit for the readers-only case, but won't argue. I certainly like the reader/writer case.
Thanks, Davidlohr
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