On Mon 02-09-19 13:34:54, 박상우 wrote: > >On Fri 30-08-19 18:25:53, Sangwoo wrote: > >> The highatomic migrate block can be increased to 1% of Total memory. > >> And, this is for only highorder ( > 0 order). So, this block size is > >> excepted during check watermark if allocation type isn't alloc_harder. > >> > >> It has problem. The usage of highatomic is already calculated at > NR_FREE_PAGES. > >> So, if we except total block size of highatomic, it's twice minus size of > allocated > >> highatomic. > >> It's cause allocation fail although free pages enough. > >> > >> We checked this by random test on my target(8GB RAM). > >> > >> Binder:6218_2: page allocation failure: order:0, mode:0x14200ca > (GFP_HIGHUSER_MOVABLE), nodemask=(null) > >> Binder:6218_2 cpuset=background mems_allowed=0 > > > >How come this order-0 sleepable allocation fails? The upstream kernel > >doesn't fail those allocations unless the process context is killed by > >the oom killer. > > Most calltacks are zsmalloc, as shown below. What makes those allocations special so that they fail unlike any other normal order-0 requests? Also do you see the same problem with the current upstream kernel? Is it possible this is an Android specific issue? > Call trace: > dump_backtrace+0x0/0x1f0 > show_stack+0x18/0x20 > dump_stack+0xc4/0x100 > warn_alloc+0x100/0x198 > __alloc_pages_nodemask+0x116c/0x1188 > do_swap_page+0x10c/0x6f0 > handle_pte_fault+0x12c/0xfe0 > handle_mm_fault+0x1d0/0x328 > do_page_fault+0x2a0/0x3e0 > do_translation_fault+0x44/0xa8 > do_mem_abort+0x4c/0xd0 > el1_da+0x24/0x84 > __arch_copy_to_user+0x5c/0x220 > binder_ioctl+0x20c/0x740 > compat_SyS_ioctl+0x128/0x248 > __sys_trace_return+0x0/0x4 -- Michal Hocko SUSE Labs
