On (12/22/16 11:53), Petr Mladek wrote: > > Thank you. I tried "[PATCHv6 0/7] printk: use printk_safe to handle printk() > > recursive calls" at https://lkml.org/lkml/2016/12/21/232 on top of linux.git > > as of commit 52bce91165e5f2db "splice: reinstate SIGPIPE/EPIPE handling", but > > it turned out that your patch set does not solve this problem. > > > > I was assuming that sending to consoles from printk() is offloaded to a kernel > > thread dedicated for that purpose, but your patch set does not do it. As a result, > > somebody who called out_of_memory() is still preempted by other threads consuming > > CPU time due to cond_resched() from console_unlock() as demonstrated by below patch. > > Ah, it was a misunderstanding. The "printk_safe" patchset allows to > call printk() from inside some areas guarded by logbuf_lock. By other > words, it allows to print errors from inside printk() code. I does > not solve the soft-/live-locks. ineeed. > We need the async printk patchset here. It will allow to offload the > console handling to the kthread. AFAIK, Sergey wanted to rebase it > on top of the printk_safe patchset. I am not sure when he want or > will have time to do so, though. sure. this is still the case. and in fact my tree here https://gitlab.com/senozhatsky/linux-next-ss/commits/printk-safe-deferred contains both patch sets: 9 patche in total (rebased agains linux-next 20161221). first 7 patches are printk-safe, the last 2 -- async printk. -ss -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>