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| author | Lutz Donnerhacke <donner@FreeBSD.org> | 2021-02-11 22:59:11 +0000 |
|---|---|---|
| committer | Lutz Donnerhacke <donner@FreeBSD.org> | 2021-05-27 10:55:52 +0000 |
| commit | 7fd88ba72eb353c9dd43063f5faea019ad5b0ea9 (patch) | |
| tree | 34081abde87f52df88ae86ffb378e0db04ef9acc | |
| parent | fb5e2f4d613eee6839f25084fdcf078081c080bc (diff) | |
| download | src-7fd88ba72eb353c9dd43063f5faea019ad5b0ea9.tar.gz src-7fd88ba72eb353c9dd43063f5faea019ad5b0ea9.zip | |
netgraph/ng_bridge: Avoid cache thrashing
Hint the compiler, that this update is needed at most once per second.
Only in this case the memory line needs to be written. This will
reduce the amount of cache trashing during forward of most frames.
Suggested by: zec
Approved by: zec
Differential Revision: https://reviews.freebsd.org/D28601
(cherry picked from commit 4dfe70fdbda05453e824bc9edfc0d09eab7b2929)
| -rw-r--r-- | sys/netgraph/ng_bridge.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/sys/netgraph/ng_bridge.c b/sys/netgraph/ng_bridge.c index 0bed50fc240b..baedeb911e6d 100644 --- a/sys/netgraph/ng_bridge.c +++ b/sys/netgraph/ng_bridge.c @@ -863,7 +863,8 @@ ng_bridge_rcvdata(hook_p hook, item_p item) * This is safe without locking, because it's * the only operation during shared access. */ - host->staleness = 0; + if (__predict_false(host->staleness > 0)) + host->staleness = 0; if ((host == NULL && ctx.incoming->learnMac) || (host != NULL && host->link != ctx.incoming)) { |