From 1ca7d67cf5d5a2aef26a8d9afd789006fa098347 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Mon, 7 Oct 2013 15:51:59 -0700 Subject: seqcount: Add lockdep functionality to seqcount/seqlock structures Currently seqlocks and seqcounts don't support lockdep. After running across a seqcount related deadlock in the timekeeping code, I used a less-refined and more focused variant of this patch to narrow down the cause of the issue. This is a first-pass attempt to properly enable lockdep functionality on seqlocks and seqcounts. Since seqcounts are used in the vdso gettimeofday code, I've provided non-lockdep accessors for those needs. I've also handled one case where there were nested seqlock writers and there may be more edge cases. Comments and feedback would be appreciated! Signed-off-by: John Stultz Signed-off-by: Peter Zijlstra Cc: Eric Dumazet Cc: Li Zefan Cc: Mathieu Desnoyers Cc: Steven Rostedt Cc: "David S. Miller" Cc: netdev@vger.kernel.org Link: http://lkml.kernel.org/r/1381186321-4906-3-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar --- include/linux/init_task.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'include/linux/init_task.h') diff --git a/include/linux/init_task.h b/include/linux/init_task.h index 5cd0f0949927..b0ed422e4e4a 100644 --- a/include/linux/init_task.h +++ b/include/linux/init_task.h @@ -32,10 +32,10 @@ extern struct fs_struct init_fs; #endif #ifdef CONFIG_CPUSETS -#define INIT_CPUSET_SEQ \ - .mems_allowed_seq = SEQCNT_ZERO, +#define INIT_CPUSET_SEQ(tsk) \ + .mems_allowed_seq = SEQCNT_ZERO(tsk.mems_allowed_seq), #else -#define INIT_CPUSET_SEQ +#define INIT_CPUSET_SEQ(tsk) #endif #define INIT_SIGNALS(sig) { \ @@ -220,7 +220,7 @@ extern struct task_group root_task_group; INIT_FTRACE_GRAPH \ INIT_TRACE_RECURSION \ INIT_TASK_RCU_PREEMPT(tsk) \ - INIT_CPUSET_SEQ \ + INIT_CPUSET_SEQ(tsk) \ INIT_VTIME(tsk) \ } -- cgit v1.2.3-59-g8ed1b