>On Mon 02-09-19 13:34:54, Sangwoo� 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? There is the other case of fail order-0 fail. ---- hvdcp_opti: page allocation failure: order:0, mode:0x1004000(GFP_NOWAIT|__GFP_COMP), nodemask=(null) hvdcp_opti cpuset=/ mems_allowed=0 CPU: 0 PID: 1882 Comm: hvdcp_opti Tainted: P S W O 4.14.83-perf+ #1 Hardware name: Qualcomm Technologies, Inc. SM6150 PM6150 LG Electronics, mh3_lao_kr, rev-C (DT) Call trace: dump_backtrace+0x0/0x1f0 show_stack+0x18/0x20 dump_stack+0xc4/0x100 warn_alloc+0x100/0x198 __alloc_pages_nodemask+0x116c/0x1188 new_slab+0x130/0x5e0 ___slab_alloc+0x490/0x610 kmem_cache_alloc+0x2a8/0x2c8 avc_alloc_node+0x34/0x268 avc_compute_av+0xb8/0x1f8 avc_has_perm_noaudit+0xcc/0x100 selinux_inode_permission+0x100/0x1b0 security_inode_permission+0x58/0x78 __inode_permission2+0x40/0xe8 may_open+0x78/0x118 path_openat+0x8f8/0x14d0 do_filp_open+0x74/0x120 do_sys_open+0x13c/0x260 SyS_openat+0x10/0x18 el0_svc_naked+0x34/0x38 snipped... DMA free:11320kB min:3440kB low:46092kB high:47812kB active_anon:143344kB inactive_anon:145812kB active_file:171900kB inactive_file:146976kB u lowmem_reserve[]: 0 1901 1901 Normal free:3928kB min:3940kB low:52748kB high:54716kB active_anon:85100kB inactive_anon:81772kB active_file:103312kB inactive_file:114732kB u lowmem_reserve[]: 0 0 0 DMA: 343*4kB (UMECH) 947*8kB (UMCH) 26*16kB (UH) 23*32kB (UH) 11*64kB (H) 6*128kB (H) 3*256kB (H) 0*512kB 0*1024kB 0*2048kB 0*4096kB = 12340kB Normal: 798*4kB (UMH) 104*8kB (UMH) 20*16kB (U) 3*32kB (UH) 11*64kB (H) 1*128kB (H) 1*256kB (H) 0*512kB 0*1024kB 0*2048kB 0*4096kB = 5528kB ---- In my test, most case are using camera. So, memory usage is increased momentarily, it cause free page go to under low value of watermark. If free page is under low and 0-order fail is occured, its normal operation. But, although free page is higher than min, fail is occurred. After fix routin for checking highatomic size, it's not reproduced. I now develop smartphone is applied kernel-4.14. And I didn't checked current upstream kernel. I thinks this symptom can be occurred the any platform that have use-case of memory intensive moment. > >> 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 >
