With LOCKDEP_CROSSRELEASE and LOCKDEP_COMPLETIONS introduced, the growth in kernel stack usage of several functions were reported: https://marc.info/?l=linux-kernel&m=150270063231284&w=2 The root cause of this is in COMPLETION_INITIALIZER_ONSTACK(), we use ({init_completion(&work); work}) , which will create a temporary object when returned. However this temporary object is unnecessary. And this patch fixes it by making the statement expression in COMPLETION_INITIALIZER_ONSTACK() return a pointer rather than a whole structure. This will reduce the stack usage even if !LOCKDEP. However, such a change does make one COMPLETION_INITIALIZER_ONSTACK() callsite invalid, so we fix this first via converting to init_completion(). Regards, Boqun -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
