o...@netbsd.org wrote: > In M_WAIT case, m_reclaim() will run and run until get mbuf cluster > if mclpool limit reached. If m_reclaim() repeatedly but cannot to > get new mbuf cluster, m_clget() will not return. > > network stacks using mbufs is use with M_DONTWAIT, but it will failed > to get new mbuf cluster in this case. "freeze" means that.
Yes, hitting the limit would trigger m_reclaim() and m_clget() would block. It is a quite similar condition to memory or KVA starvation. However, why such blocking in sosend() is problematic, or, how is it different from any other WAITOK allocation? I see the point about the limit. Inadequately low limit may cause many blocking processes, while there is still a lot of memory. However, in such case, perhaps you want PR_LIMITFAIL, instead of PR_NOWAIT? Note that PR_NOWAIT (M_DONTWAIT) has other implications, e.g. it might fail due to try-locks. So, I think your fix is incorrect. Thanks. -- Mindaugas
