Re: [PATCH] mm,page_alloc: softlockup on warn_alloc on
From: Michal Hocko <mhocko@suse.com>
Date: 2017-09-15 12:00:25
On Fri 15-09-17 20:38:49, Tetsuo Handa wrote: [...]
You said "identify _why_ we see the lockup trigerring in the first place" without providing means to identify it. Unless you provide means to identify it (in a form which can be immediately and easily backported to 4.9 kernels; that is, backporting not-yet-accepted printk() offloading patchset is not a choice), this patch cannot be refused.
I fail to see why. It simply workarounds an existing problem elsewhere in the kernel without deeper understanding on where the problem is. You can add your own instrumentation to debug and describe the problem. This is no different to any other kernel bugs... If our printk implementation is so weak it cannot cope with writers then that should be fixed without spreading hacks in different subsystems. If the lockup is a real problem under normal workloads (rather than artificial ones) then we should try to throttle more aggresively. -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>