lockdep: Reduce stack_trace usage
When calling check_prevs_add(), if all validations passed add_lock_to_list() will add new lock to dependency tree and alloc stack_trace for each list_entry. But at this time, we are always on the same stack, so stack_trace for each list_entry has the same value. This is redundant and eats up lots of memory which could lead to warning on low MAX_STACK_TRACE_ENTRIES. Use one copy of stack_trace instead. V2: As suggested by Peter Zijlstra, move save_trace() from check_prevs_add() to check_prev_add(). Add tracking for trylock dependence which is also redundant. Signed-off-by: NYong Zhang <yong.zhang0@windriver.com> Cc: David S. Miller <davem@davemloft.net> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20100504065711.GC10784@windriver.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
Showing
想要评论请 注册 或 登录