<<On Sun, 12 Sep 1999 23:19:13 -0400 (EDT), Bosko Milekic <[email protected]> said:
> This message is in MIME format. The first part should be readable text, > while the remaining parts are likely unreadable without MIME-aware tools. > Send mail to [email protected] for more info. It would be preferable if text were sent as text, since MIME-encoded patches require more effort to read. > I'm also aware of the possiblity of some people not liking the > fact that we tsleep() forever (e.g. tsleep(x,x,x,0)). I don't have any problem with sleeping forever -- but I am concerned about the possibility of deadlock, especially when client-NFS is involved. If the problem just moves around and has harder-to-recover symptoms, the change isn't helping. The 4.3BSD code had two different behaviors: - For clusters, if M_WAIT was specified and there was no space left in mb_map, it panicked. However, m_clalloc was never called with M_WAIT, so that panic was effectively dead code. - For mbufs, if M_WAIT was specified and there were no mbufs available, it would sleep at PZERO - 1 (which was interruptible). In 4.3, the code was able to deal with cluster allocation failing. We have a somewhat different situation now, because many network interface devices have less-flexible DMA mechanisms which don't allow packet reception into non-contiguous buffers, so we need to have at least a certain number of clusters available for this purpose. -GAWollman -- Garrett A. Wollman | O Siem / We are all family / O Siem / We're all the same [email protected] | O Siem / The fires of freedom Opinions not those of| Dance in the burning flame MIT, LCS, CRS, or NSA| - Susan Aglukark and Chad Irschick To Unsubscribe: send mail to [email protected] with "unsubscribe freebsd-hackers" in the body of the message
