On (10/10/18 13:35), Michal Hocko wrote: > > Just flooding out of memory messages can trigger RCU stall problems. > > For example, a severe skbuff_head_cache or kmalloc-512 leak bug is causing > > [...] > > Quite some of them, indeed! I guess we want to rate limit the output. > What about the following? A bit unrelated, but while we are at it: I like it when we rate-limit printk-s that lookup the system. But it seems that default rate-limit values are not always good enough, DEFAULT_RATELIMIT_INTERVAL / DEFAULT_RATELIMIT_BURST can still be too verbose. For instance, when we have a very slow IPMI emulated serial console -- e.g. baud rate at 57600. DEFAULT_RATELIMIT_INTERVAL and DEFAULT_RATELIMIT_BURST can add new OOM headers and backtraces faster than we evict them. Does it sound reasonable enough to use larger than default rate-limits for printk-s in OOM print-outs? OOM reports tend to be somewhat large and the reported numbers are not always *very* unique. What do you think? -ss
