Dear Greg, Very sorry my mail history is lost. I found a part of ION memory will be return to system in android platform, But these memorys can’t accounted in low-memory-killer strategy. … And I also found ION memory comes from, kmalloc/vmalloc/alloc pages/reserved memory. I understand reserved memory shouldn't accounted to free memory. But the memory which alloced by kmalloc/vmalloc/alloc pages, can be reclaimed. But the low-memory killer can't accounted this part, Many thanks. Code location, ---> drivers/staging/android/lowmemorykiller.c -> lowmem_scan Code review, 415 other_free = global_page_state(NR_FREE_PAGES); 416 417 if (global_page_state(NR_SHMEM) + global_page_state(NR_MLOCK) + total_swapcache_pages() < 418 global_page_state(NR_FILE_PAGES) + zcache_pages()) 419 other_file = global_page_state(NR_FILE_PAGES) + zcache_pages() - 420 global_page_state(NR_SHMEM) - 422 total_swapcache_pages(); So, other_free means: MemFree, other_file means: Buffers + Cached - ShMEM - SwapCache. And part of ( IonInUse - IonTotal ) should be reclaimed but not accounted. Thanks. Meminfo example $ adb shell cat /proc/meminfo MemTotal: 3805312 kB MemFree: 1446220 kB MemAvailable: 2388384 kB Buffers: 16796 kB Cached: 1190868 kB … IonTotal: 224252 kB IonInUse: 199108 kB Thanks BR Zhiyuan zhu -----Original Message----- From: Greg KH [mailto:gregkh@xxxxxxxxxxxxxxxxxxx] Sent: Monday, May 15, 2017 4:06 PM To: Zhiyuan Zhu(朱志遠) Cc: vinmenon@xxxxxxxxxxxxxx; linux-mm@xxxxxxxxx; skhiani@xxxxxxxxxxxxxx; torvalds@xxxxxxxxxxxxxxxxxxxx Subject: Re: Low memory killer problem On Mon, May 15, 2017 at 07:25:20AM +0000, zhiyuan_zhu@xxxxxxx wrote: > Loop MM maintainers, > > > > Dear All, > > > > Who can talk about this problem? Thanks. What problem? > Maybe this is lowmemory killer’s bug ? This code is now removed from the kernel, so I doubt there could be a bug in it :) > ION memory is complex now, we need to have a breakdown for them, I think. What do you mean by this? thanks, greg k-h ��.n������g��� �a��� �&ޖ)���)��h���&������梷���� �Ǟ�m������)������^�����������v���O��zf������
