Date: Fri, 27 Jan 2017 08:32:50 +0000 (UTC) From: Hans Petter Selasky <hselasky@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r312865 - head/sys/dev/mlx5/mlx5_en Message-ID: <201701270832.v0R8WoGG085361@repo.freebsd.org>
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Author: hselasky Date: Fri Jan 27 08:32:50 2017 New Revision: 312865 URL: https://svnweb.freebsd.org/changeset/base/312865 Log: Enforce reading the consumer and producer counters once to ensure consistent return values from the mlx5e_sq_has_room_for() function. The two counters are incremented by different threads under different locks. MFC after: 1 week Sponsored by: Mellanox Technologies Modified: head/sys/dev/mlx5/mlx5_en/en.h Modified: head/sys/dev/mlx5/mlx5_en/en.h ============================================================================== --- head/sys/dev/mlx5/mlx5_en/en.h Fri Jan 27 08:30:43 2017 (r312864) +++ head/sys/dev/mlx5/mlx5_en/en.h Fri Jan 27 08:32:50 2017 (r312865) @@ -546,8 +546,10 @@ struct mlx5e_sq { static inline bool mlx5e_sq_has_room_for(struct mlx5e_sq *sq, u16 n) { - return ((sq->wq.sz_m1 & (sq->cc - sq->pc)) >= n || - sq->cc == sq->pc); + u16 cc = sq->cc; + u16 pc = sq->pc; + + return ((sq->wq.sz_m1 & (cc - pc)) >= n || cc == pc); } struct mlx5e_channel {
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