On Wed 10-10-18 20:48:33, Sergey Senozhatsky wrote: > 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? I do not really care about the current inerval/burst values. This change should be done seprately and ideally with some numbers. -- Michal Hocko SUSE Labs
