On Thu, Dec 16, 2010 at 12:26:03AM -0800, Andrew Morton wrote: > Patches have gone a bit stale, sorry. Refactoring in > kernel/cgroup_freezer.c necessitates a refresh and retest please. commit 53feb29767c29c877f9d47dcfe14211b5b0f7ebd changed a bunch of stuff in kernel/cpuset.c to allocate nodemasks with NODEMASK_ALLOC (which wraps kmalloc) instead of on the stack. 1. All these functions have 'void' return values, indicating that calling them them must not fail. Sure there are bailout cases, but no semblance of cross-function error propagation. Most importantly, cpuset_attach is a subsystem callback, which MUST not fail given the way it's used in cgroups, so relying on kmalloc is not safe. 2. I'm working on a patch series which needs to hold tasklist_lock across ss->attach callbacks (in cpuset_attach's "if (threadgroup)" case, this is how safe traversal of tsk->thread_group will be ensured), and kmalloc isn't allowed while holding a spin-lock. Why do we need heap-allocation here at all? In each case their scope is exactly the function's scope, and neither the commit nor the surrounding patch series give any explanation. I'd like to revert the patch if possible. cc'ing Miao Xie (author) and David Rientjes (acker). -- Ben _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers
