On Tue, 2015-10-27 at 16:37 -0700, Stephane Eranian wrote: > But that macro is already embedded into the task_css_set() macro. > What we are saying here is that we have another way of ensuring the > cgroup cannot disappear here, and thus the rcu lockdep detects we > are not holding the rcu read lock but we know this is okay. We are > trying to avoid grabbing the rcu read lock when it is not really needed > to guarantee correct execution. So we are just shutting up the lockdep > in these particular cases by passing true as the safe argument value.
Sure, but in lockdep verbs, the following : + /* holding ctx->lock, so cgroup access is safe */ + cgrp = perf_cgroup_from_task(task, true); would map to : cgrp = perf_cgroup_from_task(task, lockdep_is_held(&ctx->lock)); Notice the comment becomes useless. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
