On Jan 24, 2008 18:32 +0100, Bodo Eggert wrote: > I think a single, system-wide signal is the second-to worst solution: All > applications (or the wrong one, if you select one) would free their caches > and start to crawl, and either stay in this state or slowly increase their > caches again until they get signaled again. And the signal would either > come too early or too late. The userspace daemon could collect the weighted > demand of memory from all applications and tell them how much to use. Well, sending a few signals (maybe to the top 5 processes in the OOM killer list) is still a LOT better than OOM-killing them without warning... That way important system processes could be taught to understand SIGDANGER and maybe do something about it instead of being killed, and if Firefox and other memory hungry processes flush some of their cache it is not fatal. I wouldn't think that SIGDANGER means "free all of your cache", since the memory usage clearly wasn't a problem a few seconds previously, so as an application writer I'd code it as "flush the oldest 10% of my cache" or similar, and the kernel could send SIGDANGER again (or kill the real offender) if the memory usage again becomes an issue. Cheers, Andreas -- Andreas Dilger Sr. Staff Engineer, Lustre Group Sun Microsystems of Canada, Inc. - 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
