search for: debug_pagealloc

...ime, mem_init hasn't been called yet (which would be called by > mm_init). Thus, the free pages are still owned by memblock. It's in mem_init > (x86/mm/init_64.c) that memblock_free_all gets called and free pages are > released. > > During testing, I've also noticed that debug_pagealloc=1 will make the issue > disappear. That's because with debug_pagealloc=1, probe_page_size_mask in > x86/mm/init.c will not allow large pages (2M/1G). Therefore, no > split_large_page would happen. Similarly, if CPU doesn't have > X86_FEATURE_PSE, there won't be large pages e...

...ccessing invalid memory: So I think there's a race with that. And I'll warn you: the kernel does do speculative reads of memory that might be invalid, not just in places like this. See the comment in get_user_huge_page() for example, where we knowingly do speculative reads, but hide it if DEBUG_PAGEALLOC is set. More commonly, CONFIG_DCACHE_WORD_ACCESS is very much about doing speculative reads. Now, that access is hidden inside an asm, so KASan won't see it, but there might well be others. You probably don't see them very much just because they are so rarely a problem, and most of the ti...

...ccessing invalid memory: So I think there's a race with that. And I'll warn you: the kernel does do speculative reads of memory that might be invalid, not just in places like this. See the comment in get_user_huge_page() for example, where we knowingly do speculative reads, but hide it if DEBUG_PAGEALLOC is set. More commonly, CONFIG_DCACHE_WORD_ACCESS is very much about doing speculative reads. Now, that access is hidden inside an asm, so KASan won't see it, but there might well be others. You probably don't see them very much just because they are so rarely a problem, and most of the ti...

...intainers of the Xen tree. MAINTAINERS: Update the Xen subsystem''s with proper mailing list. xen: replace strict_strtoul() with kstrtoul() ... grep: /proc/filesystems: No such file or directory Starting Bootlog daemon: [ 4.136137] double fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC [ 4.137521] CPU: 0 PID: 132 Comm: bootlogd Not tainted 3.12.0-rc2-00153-g14951f2 #129 [ 4.139156] task: ffff88000c9a6580 ti: ffff88000c9ba000 task.ti: ffff88000c9ba000 [ 4.140042] RIP: 0010:[<ffffffff81f31c7e>] [<ffffffff81f31c7e>] boot_tvec_bases+0x1fe/0x2080 [ 4.140042] R...

...someone else from the stack, please let me know. [ 72.322236] BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 [ 72.329993] IP: [<ffffffff8153c1a0>] tun_device_event+0x110/0x340 [ 72.336032] PGD 7f054f1067 PUD 7ef6f3f067 PMD 0 [ 72.340616] Oops: 0002 [#1] SMP DEBUG_PAGEALLOC [ 72.345498] gsmi: Log Shutdown Reason 0x03 [ 72.349541] Modules linked in: w1_therm wire cdc_acm ehci_pci ehci_hcd mlx4_en ib_uverbs mlx4_ib ib_core mlx4_core [ 72.359870] CPU: 12 PID: 7820 Comm: set.ixion-haswe Not tainted 4.7.0-dbx-DEV #10 [ 72.360253] mlx4_en: eth0: Link Up [ 72.37061...

...someone else from the stack, please let me know. [ 72.322236] BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 [ 72.329993] IP: [<ffffffff8153c1a0>] tun_device_event+0x110/0x340 [ 72.336032] PGD 7f054f1067 PUD 7ef6f3f067 PMD 0 [ 72.340616] Oops: 0002 [#1] SMP DEBUG_PAGEALLOC [ 72.345498] gsmi: Log Shutdown Reason 0x03 [ 72.349541] Modules linked in: w1_therm wire cdc_acm ehci_pci ehci_hcd mlx4_en ib_uverbs mlx4_ib ib_core mlx4_core [ 72.359870] CPU: 12 PID: 7820 Comm: set.ixion-haswe Not tainted 4.7.0-dbx-DEV #10 [ 72.360253] mlx4_en: eth0: Link Up [ 72.37061...

...ned -22 [29175] Random reseed: 2776471322 [29175] Random reseed: 3086119361 child 2606 exiting [29175] Bailing main loop. Exit reason: ctrl-c [179906.393060] ------------[ cut here ]------------ [179906.396341] kernel BUG at /build/linux/mm/slub.c:3352! [179906.399693] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC [179906.403272] CPU: 0 PID: 29175 Comm: trinity-main Not tainted 3.10.0-rc4 #1 [179906.407692] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [179906.411475] task: ffff8800b69e47c0 ti: ffff880092f2e000 task.ti: ffff880092f2e000 [179906.416305] RIP: 0010:[<ffffffff81225255>] [<ffffffff8...

...ned -22 [29175] Random reseed: 2776471322 [29175] Random reseed: 3086119361 child 2606 exiting [29175] Bailing main loop. Exit reason: ctrl-c [179906.393060] ------------[ cut here ]------------ [179906.396341] kernel BUG at /build/linux/mm/slub.c:3352! [179906.399693] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC [179906.403272] CPU: 0 PID: 29175 Comm: trinity-main Not tainted 3.10.0-rc4 #1 [179906.407692] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [179906.411475] task: ffff8800b69e47c0 ti: ffff880092f2e000 task.ti: ffff880092f2e000 [179906.416305] RIP: 0010:[<ffffffff81225255>] [<ffffffff8...

Hi, 2.6.29-rc3 x86_64 guest on x86_64 RHEL5.3 host: https://bugzilla.redhat.com/484295 kernel BUG at mm/filemap.c:123! invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC last sysfs file: /sys/devices/vbd-51712/block/xvda/xvda2/dev CPU 0 Modules linked in: ipv6 xts lrw gf128mul sha256_generic cbc dm_crypt dm_round_robin dm_multipath btrfs zlib_deflate libcrc32c xfs exportfs jfs reiserfs gfs2 msdos linear r...

...2776471322 > [29175] Random reseed: 3086119361 > child 2606 exiting > [29175] Bailing main loop. Exit reason: ctrl-c > [179906.393060] ------------[ cut here ]------------ > [179906.396341] kernel BUG at /build/linux/mm/slub.c:3352! > [179906.399693] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC > [179906.403272] CPU: 0 PID: 29175 Comm: trinity-main Not tainted 3.10.0-rc4 #1 > [179906.407692] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 > [179906.411475] task: ffff8800b69e47c0 ti: ffff880092f2e000 task.ti: > ffff880092f2e000 > [179906.416305] RIP: 0010:[<ffffffff8122...

...then. Jason, any idea? > [ 72.322236] BUG: unable to handle kernel NULL pointer dereference > at 0000000000000010 > [ 72.329993] IP: [<ffffffff8153c1a0>] tun_device_event+0x110/0x340 > [ 72.336032] PGD 7f054f1067 PUD 7ef6f3f067 PMD 0 > [ 72.340616] Oops: 0002 [#1] SMP DEBUG_PAGEALLOC > [ 72.345498] gsmi: Log Shutdown Reason 0x03 > [ 72.349541] Modules linked in: w1_therm wire cdc_acm ehci_pci > ehci_hcd mlx4_en ib_uverbs mlx4_ib ib_core mlx4_core > [ 72.359870] CPU: 12 PID: 7820 Comm: set.ixion-haswe Not tainted > 4.7.0-dbx-DEV #10 > [ 72.360253] mlx4_...

...via KVM, host Fedora 20, guest Fedora 20. my config is at: https://fedorapeople.org/~grover/config-20141110 [ 0.828494] ------------[ cut here ]------------ [ 0.829039] kernel BUG at /home/agrover/git/kernel/include/linux/virtio_config.h:125! [ 0.831266] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC [ 0.831266] Modules linked in: [ 0.831266] CPU: 1 PID: 30 Comm: kworker/1:1 Not tainted 3.18.0-rc4 #120 [ 0.831266] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 0.831266] Workqueue: events control_work_handler [ 0.831266] task: ffff88003cd98000 ti: ffff88003cd94000 task.ti: f...

...rentMemory=0.5*Memory (thanks to Christian for the hint) - as virtio-ccw is enabling virtio-1 by default: [ 3.273419] ------------[ cut here ]------------ [ 3.273424] Kernel BUG at 0000000000300df2 [verbose debug info unavailable] [ 3.273617] illegal operation: 0001 ilc:1 [#1] PREEMPT SMP DEBUG_PAGEALLOC [ 3.273623] Modules linked in: autofs4 [ 3.273627] CPU: 2 PID: 1 Comm: systemd Not tainted 4.5.0-00798-g1181f16 #6 [ 3.273629] task: 000000003def8000 ti: 000000003deec000 task.ti: 000000003deec000 [ 3.273631] Krnl PSW : 0704d00180000000 0000000000300df2 (do_iter_readv_writev+0x2/0x90) [...

...rentMemory=0.5*Memory (thanks to Christian for the hint) - as virtio-ccw is enabling virtio-1 by default: [ 3.273419] ------------[ cut here ]------------ [ 3.273424] Kernel BUG at 0000000000300df2 [verbose debug info unavailable] [ 3.273617] illegal operation: 0001 ilc:1 [#1] PREEMPT SMP DEBUG_PAGEALLOC [ 3.273623] Modules linked in: autofs4 [ 3.273627] CPU: 2 PID: 1 Comm: systemd Not tainted 4.5.0-00798-g1181f16 #6 [ 3.273629] task: 000000003def8000 ti: 000000003deec000 task.ti: 000000003deec000 [ 3.273631] Krnl PSW : 0704d00180000000 0000000000300df2 (do_iter_readv_writev+0x2/0x90) [...

virtio spec 0.9.X requires DRIVER_OK to be set before VQs are used, but some drivers use VQs before probe function returns. Since DRIVER_OK is set after probe, this violates the spec. Even though under virtio 1.0 transitional devices support this behaviour, we want to make it possible for those early callers to become spec compliant and eventually support non-transitional devices. Add API for

virtio spec 0.9.X requires DRIVER_OK to be set before VQs are used, but some drivers use VQs before probe function returns. Since DRIVER_OK is set after probe, this violates the spec. Even though under virtio 1.0 transitional devices support this behaviour, we want to make it possible for those early callers to become spec compliant and eventually support non-transitional devices. Add API for

Xen: 3.1.2 (or thereabouts), 64bit dom0: 2.6.18.8, pae pv-ops, 2.6.26 BUG: unable to handle kernel paging request at 69746174 IP: [<c015e221>] move_freepages+0x61/0xc0 *pdpt = 0000000204ed6007 Oops: 0002 [#1] SMP Modules linked in: Pid: 6859, comm: sh Not tainted (2.6.26-linode13 #1) EIP: 0061:[<c015e221>] EFLAGS: 00010002 CPU: 2 EIP is at move_freepages+0x61/0xc0 EAX: 69746174 EBX:

Xen: 3.1.2 (or thereabouts), 64bit dom0: 2.6.18.8, pae pv-ops, 2.6.26 BUG: unable to handle kernel paging request at 69746174 IP: [<c015e221>] move_freepages+0x61/0xc0 *pdpt = 0000000204ed6007 Oops: 0002 [#1] SMP Modules linked in: Pid: 6859, comm: sh Not tainted (2.6.26-linode13 #1) EIP: 0061:[<c015e221>] EFLAGS: 00010002 CPU: 2 EIP is at move_freepages+0x61/0xc0 EAX: 69746174 EBX:

...>] sysenter_do_call+0x12/0x31 [ 297.416145] ---[ end trace 4eaa2a86a8e2da24 ]--- [ 297.416621] BUG: unable to handle kernel NULL pointer dereference at 000001f4 [ 297.416915] IP: [<c01addd2>] bio_get_nr_vecs+0xf/0x3f [ 297.417199] *pde = 00000000 [ 297.417398] Oops: 0000 [#1] PREEMPT DEBUG_PAGEALLOC [ 297.417706] last sysfs file: /sys/block/ram9/range [ 297.417908] Modules linked in: [ 297.418086] [ 297.418161] Pid: 5144, comm: mount Tainted: G W (2.6.29-rc1-00195-g1df11ad #200) System Name [ 297.418161] EIP: 0060:[<c01addd2>] EFLAGS: 00010246 CPU: 0 [ 297.418161] EIP is at...

Hello, I have been having some crashes like this. Since I upgraded to 3.6.4 they have become common. The crashes happen pretty randomly during normal system usage. After the syslog messages the system stays semi usable for a minute, but when I run any new program it hangs. I had to downgrade to 3.6.2 to get my system usable again. Is there any way I can help find the cause of those crashes?