From: Eric Dumazet <[EMAIL PROTECTED]> Date: Tue, 11 Sep 2007 14:56:13 +0200
> When the periodic IP route cache flush is done (every 600 seconds on > default configuration), some hosts suffer a lot and eventually trigger > the "soft lockup" message. > > dst_run_gc() is doing a scan of a possibly huge list of dst_entries, > eventually freeing some (less than 1%) of them, while holding the > dst_lock spinlock for the whole scan. > > Then it rearms a timer to redo the full thing 1/10 s later... > The slowdown can last one minute or so, depending on how active are > the tcp sessions. > > This second version of the patch converts the processing from a softirq > based one to a workqueue. > > Even if the list of entries in garbage_list is huge, host is still > responsive to softirqs and can make progress. > > Instead of reseting gc timer to 0.1 second if one entry was freed in a > gc run, we do this if more than 10% of entries were freed. I like this patch a lot, some minor fix is needed though: > + __builtin_prefetch(&next->next, 1, 0); Please use prefetch() instead of a direct explicit call to a gcc-specific routine :-) - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
