On Sat, 15 Sep 2007 03:41:26 -0700 Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > eww, kmap. Large amounts of them, apparently. > > Be aware that kmap is a) slow and b) deadlockable. The latter happens when > multiple tasks want to take more than one kmap simultaneously: they all > wait for someone else to release one. Your code here seems especially > vulnerable to this. > > Nick had a kmap-speedup patchset a while back which addressed a) but I > don't know if it addressed the deadlock. But that patch seemed to die. That would've been me. What I did to address b) is to pre-allocate each kmap user a second kmap slot. Of course this isn't water-tight either. These patches are part of -rt, I could respin against mainline if there is interest. - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
