On Thu, Mar 3, 2016 at 5:41 PM, Anshuman Khandual <khandual@xxxxxxxxxxxxxxxxxx> wrote: > On 03/03/2016 12:31 PM, Li Zhang wrote: >> From: Li Zhang <zhlcindy@xxxxxxxxxxxxxxxxxx> >> >> This patch is based on Mel Gorman's old patch in the mailing list, >> https://lkml.org/lkml/2015/5/5/280 which is dicussed but it is > > Typo here ....................................^^^^^^^^ > Sorry, I will correct it. > >> fixed with a completion to wait for all memory initialised in >> page_alloc_init_late(). It is to fix the oom problem on X86 > > You can just write *out of memory* instead of *oom* or put them in > capitals. > OK >> with 24TB memory which allocates memory in late initialisation. >> But for Power platform with 32TB memory, it causes a call trace >> in vfs_caches_init->inode_init() and inode hash table needs more >> memory. >> So this patch allocates 1GB for 0.25TB/node for large system >> as it is mentioned in https://lkml.org/lkml/2015/5/1/627 > > I am wondering how its going to impact other architectures. I just saw some discussion for X86 in https://lkml.org/lkml/2015/5/1/627. And some tests are done for X86 with huge memory. >From code view, this allocate more memory in early initialisation, it may cause boot time a little bit. >> >> This call trace is found on Power with 32TB memory, 1024CPUs, 16nodes. >> The log from dmesg as the following: >> >> [ 0.091780] Dentry cache hash table entries: 2147483648 (order: 18, >> 17179869184 bytes) >> [ 2.891012] vmalloc: allocation failure, allocated 16021913600 of >> 17179934720 bytes >> [ 2.891034] swapper/0: page allocation failure: order:0, >> mode:0x2080020 >> [ 2.891038] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.0-0-ppc64 >> [ 2.891041] Call Trace: >> [ 2.891046] [c0000000012bfa00] [c0000000007c4a50] >> .dump_stack+0xb4/0xb664 (unreliable) >> [ 2.891051] [c0000000012bfa80] [c0000000001f93d4] >> .warn_alloc_failed+0x114/0x160 >> [ 2.891054] [c0000000012bfb30] [c00000000023c204] >> .__vmalloc_area_node+0x1a4/0x2b0 >> [ 2.891058] [c0000000012bfbf0] [c00000000023c3f4] >> .__vmalloc_node_range+0xe4/0x110 >> [ 2.891061] [c0000000012bfc90] [c00000000023c460] >> .__vmalloc_node+0x40/0x50 >> [ 2.891065] [c0000000012bfd10] [c000000000b67d60] >> .alloc_large_system_hash+0x134/0x2a4 >> [ 2.891068] [c0000000012bfdd0] [c000000000b70924] >> .inode_init+0xa4/0xf0 >> [ 2.891071] [c0000000012bfe60] [c000000000b706a0] >> .vfs_caches_init+0x80/0x144 >> [ 2.891074] [c0000000012bfef0] [c000000000b35208] >> .start_kernel+0x40c/0x4e0 >> [ 2.891078] [c0000000012bff90] [c000000000008cfc] >> start_here_common+0x20/0x4a4 >> [ 2.891080] Mem-Info: > > The dmesg output here needs some formatting. > >> >> Signed-off-by: Li Zhang <zhlcindy@xxxxxxxxxxxxxxxxxx> >> --- >> mm/page_alloc.c | 11 +++++++++-- >> 1 file changed, 9 insertions(+), 2 deletions(-) >> >> diff --git a/mm/page_alloc.c b/mm/page_alloc.c >> index 838ca8bb..4847f25 100644 >> --- a/mm/page_alloc.c >> +++ b/mm/page_alloc.c >> @@ -293,13 +293,20 @@ static inline bool update_defer_init(pg_data_t *pgdat, >> unsigned long pfn, unsigned long zone_end, >> unsigned long *nr_initialised) >> { >> + unsigned long max_initialise; >> + >> /* Always populate low zones for address-contrained allocations */ >> if (zone_end < pgdat_end_pfn(pgdat)) >> return true; >> + /* >> + * Initialise at least 2G of a node but also take into account that >> + * two large system hashes that can take up 1GB for 0.25TB/node. >> + */ >> + max_initialise = max(2UL << (30 - PAGE_SHIFT), >> + (pgdat->node_spanned_pages >> 8)); >> >> - /* Initialise at least 2G of the highest zone */ >> (*nr_initialised)++; >> - if (*nr_initialised > (2UL << (30 - PAGE_SHIFT)) && >> + if ((*nr_initialised > max_initialise) && > > Does this change need to be tested on all architectures ? Currently, this feature is only supported for X86 in upstream. It can be tested more in the future if some architectures need to enable it. -- Best Regards -Li -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>