Date: Thu, 25 Feb 2021 10:02:26 GMT From: Lutz Donnerhacke <donner@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: 1c0b19f9966d - stable/12 - netgraph/ng_bridge: Document staleness in multithreaded operation Message-ID: <202102251002.11PA2Qt9019006@gitrepo.freebsd.org>
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The branch stable/12 has been updated by donner: URL: https://cgit.FreeBSD.org/src/commit/?id=1c0b19f9966dd13db7202b44ca79d2170b4f7b8f commit 1c0b19f9966dd13db7202b44ca79d2170b4f7b8f Author: Lutz Donnerhacke <donner@FreeBSD.org> AuthorDate: 2021-02-09 11:32:46 +0000 Commit: Lutz Donnerhacke <donner@FreeBSD.org> CommitDate: 2021-02-25 10:02:06 +0000 netgraph/ng_bridge: Document staleness in multithreaded operation In the data path of ng_bridge(4), the only value of the host struct, which needs to be modified, is the staleness, which is reset every time a frame is received. It's save to leave the code as it is. This patch is part of a series to make ng_bridge(4) multithreaded. Reviewed by: kp Differential Revision: https://reviews.freebsd.org/D28546 (cherry picked from commit 011b7317dbb5038a95b9b4fca050325a62f3991e) --- sys/netgraph/ng_bridge.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/sys/netgraph/ng_bridge.c b/sys/netgraph/ng_bridge.c index 0b2b7f5ca6a3..3d1dc88af3c2 100644 --- a/sys/netgraph/ng_bridge.c +++ b/sys/netgraph/ng_bridge.c @@ -808,8 +808,10 @@ ng_bridge_rcvdata(hook_p hook, item_p item) /* Look up packet's source Ethernet address in hashtable */ if ((host = ng_bridge_get(priv, eh->ether_shost)) != NULL) { - - /* Update time since last heard from this host */ + /* Update time since last heard from this host. + * This is safe without locking, because it's + * the only operation during shared access. + */ host->staleness = 0; /* Did host jump to a different link? */
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