On Thu, Nov 29, 2018 at 04:49:22PM +0100, Michal Hocko wrote: >On Thu 29-11-18 15:04:49, Wei Yang wrote: >> On Thu, Nov 29, 2018 at 09:17:03AM +0100, Michal Hocko wrote: >> >On Thu 29-11-18 05:08:15, Wei Yang wrote: >> >> Function show_mem() is used to print system memory status when user >> >> requires or fail to allocate memory. Generally, this is a best effort >> >> information and not willing to affect core mm subsystem. >> > >> >I would drop the part after and >> > >> >> The data protected by pgdat_resize_lock is mostly correct except there is: >> >> >> >> * page struct defer init >> >> * memory hotplug >> > >> >This is more confusing than helpful. I would just drop it. >> > >> >The changelog doesn't explain what is done and why. The second one is >> >much more important. I would say this >> > >> >" >> >Function show_mem() is used to print system memory status when user >> >requires or fail to allocate memory. Generally, this is a best effort >> >information so any races with memory hotplug (or very theoretically an >> >early initialization) should be toleratable and the worst that could >> >happen is to print an imprecise node state. >> > >> >Drop the resize lock because this is the only place which might hold the >> >> As I mentioned in https://patchwork.kernel.org/patch/10689759/, there is >> one place used in __remove_zone(). I don't get your suggestion of this >> place. And is __remove_zone() could be called in IRQ context? > >It is only called from __remove_pages and that one calls cond_resched so >obviosly not. > Forgive my poor background knowledge, I went throught the code, but not found where call cond_resched. __remove_pages() release_mem_region_adjustable() clear_zone_contiguous() __remove_section() unregister_memory_section() __remove_zone() sparse_remove_one_section() set_zone_contiguous() Would you mind giving me a hint? >-- >Michal Hocko >SUSE Labs -- Wei Yang Help you, Help me
