On Fri, Dec 16, 2016 at 4:00 AM, Vlastimil Babka <vbabka@xxxxxxx> wrote: > On architectures that allow memory holes, page_is_buddy() has to perform > page_to_pfn() to check for the memory hole. After the previous patch, we have > the pfn already available in __free_one_page(), which is the only caller of > page_is_buddy(), so move the check there and avoid page_to_pfn(). > > Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx> > Acked-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> git bisect says this patch is the cause of an ia64 crash early in boot. Reverting 13ad59df67f19788f6c22985b1a33e466eceb643 from v4.11-rc1 makes it boot again. The commit messages talks about the "only caller" of page_is_buddy(). But grep shows two call sites: mm/page_alloc.c:816: if (!page_is_buddy(page, buddy, order)) mm/page_alloc.c:876: if (page_is_buddy(higher_page, higher_buddy, order + 1)) { The crash happens due to a bad pointer in free_one_page() Initmem setup node 0 [mem 0x0000000001000000-0x00000004fbffffff] Built 1 zonelists in Node order, mobility grouping on. Total pages: 260199 Policy zone: Normal Kernel command line: BOOT_IMAGE=scsi0:\efi\SuSE\l-bisect.gz console=tty1 console=uart,io,0x3f8 intel_iommu=off root=/dev/sda3 DMAR: IOMMU disabled PID hash table entries: 4096 (order: -1, 32768 bytes) Sorting __ex_table... software IO TLB [mem 0x060b0000-0x0a0b0000] (64MB) mapped at [e0000000060b0000-e00000000a0affff] Unable to handle kernel paging request at virtual address a07fffffffc80018 swapper[0]: Oops 11012296146944 [1] Modules linked in: CPU: 0 PID: 0 Comm: swapper Not tainted 4.10.0-bisect-06032-g13ad59d #12 task: a000000101300000 task.stack: a000000101300000 psr : 00001210084a2010 ifs : 8000000000000a98 ip : [<a0000001001cc1e1>] Not tainted (4.10.0-bisect-06032-g13ad59d) ip is at free_one_page+0x561/0x740 unat: 0000000000000000 pfs : 0000000000000a98 rsc : 0000000000000003 rnat: 20c49ba5e353f7cf bsps: 04ba52743edc9494 pr : 966696816682aa69 ldrs: 0000000000000000 ccv : 00000000000355b9 fpsr: 0009804c8a70433f csd : 0930ffff00063000 ssd : 0930ffff00063000 b0 : a0000001001cc170 b6 : a0000001011a43c0 b7 : a000000100721ba0 f6 : 000000000000000000000 f7 : 1003e0044b82fa09b5a53 f8 : 1003e0000000000000000 f9 : 1003e00000000000016e8 f10 : 1003e0000000000000008 f11 : 1003e20c49ba5e353f7cf r1 : a000000101a8ef60 r2 : 000000000000000e r3 : 0000000000000000 r8 : 0000000000000001 r9 : 0000000000000000 r10 : 0000000000230000 r11 : 000000000004fc00 r12 : a00000010130fdb0 r13 : a000000101300000 r14 : 0000000000000000 r15 : a07fffffffc80000 r16 : ffffffffffff0000 r17 : 0000000000000001 r18 : a07fffffffdd0037 r19 : 000000000000000c r20 : 0000000000000001 r21 : a00000010130fdcc r22 : 0000000000044000 r23 : ffffffffffffff80 r24 : a07fffffffd60018 r25 : 0010000000000000 r26 : 0010000000000000 r27 : a07fffffffd60030 r28 : 0000000000000100 r29 : a0000001018b99c8 r30 : a0000001018b99c8 r31 : 000000000004fc00 unwind: cannot stack reg state! unwind.desc_label_state(): out of memory unwind: stack underflow! unwind: failed to find state labeled 0x1 -- 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>