Frequency scaling not working. #17

zakwiggy · 2013-09-28T10:34:44Z

My CPU overheats and i'm getting error messages saying that max frequency is 782Mhz and that the current frequency is 996Mhz.

…optimizations Recent GCC versions (e.g. GCC-4.7.2) perform optimizations based on assumptions about the implementation of memset and similar functions. The current ARM optimized memset code does not return the value of its first argument, as is usually expected from standard implementations. For instance in the following function: void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter) { memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter)); waiter->magic = waiter; INIT_LIST_HEAD(&waiter->list); } compiled as: 800554d0 <debug_mutex_lock_common>: 800554d0: e92d4008 push {r3, lr} 800554d4: e1a00001 mov r0, r1 800554d8: e3a02010 mov r2, imx6-dongle#16 ; 0x10 800554dc: e3a01011 mov r1, imx6-dongle#17 ; 0x11 800554e0: eb04426e bl 80165ea0 <memset> 800554e4: e1a03000 mov r3, r0 800554e8: e583000c str r0, [r3, imx6-dongle#12] 800554ec: e5830000 str r0, [r3] 800554f0: e5830004 str r0, [r3, imx6-dongle#4] 800554f4: e8bd8008 pop {r3, pc} GCC assumes memset returns the value of pointer 'waiter' in register r0; causing register/memory corruptions. This patch fixes the return value of the assembly version of memset. It adds a 'mov' instruction and merges an additional load+store into existing load/store instructions. For ease of review, here is a breakdown of the patch into 4 simple steps: Step 1 ====== Perform the following substitutions: ip -> r8, then r0 -> ip, and insert 'mov ip, r0' as the first statement of the function. At this point, we have a memset() implementation returning the proper result, but corrupting r8 on some paths (the ones that were using ip). Step 2 ====== Make sure r8 is saved and restored when (! CALGN(1)+0) == 1: save r8: - str lr, [sp, #-4]! + stmfd sp!, {r8, lr} and restore r8 on both exit paths: - ldmeqfd sp!, {pc} @ Now <64 bytes to go. + ldmeqfd sp!, {r8, pc} @ Now <64 bytes to go. (...) tst r2, imx6-dongle#16 stmneia ip!, {r1, r3, r8, lr} - ldr lr, [sp], imx6-dongle#4 + ldmfd sp!, {r8, lr} Step 3 ====== Make sure r8 is saved and restored when (! CALGN(1)+0) == 0: save r8: - stmfd sp!, {r4-r7, lr} + stmfd sp!, {r4-r8, lr} and restore r8 on both exit paths: bgt 3b - ldmeqfd sp!, {r4-r7, pc} + ldmeqfd sp!, {r4-r8, pc} (...) tst r2, imx6-dongle#16 stmneia ip!, {r4-r7} - ldmfd sp!, {r4-r7, lr} + ldmfd sp!, {r4-r8, lr} Step 4 ====== Rewrite register list "r4-r7, r8" as "r4-r8". Signed-off-by: Ivan Djelic <ivan.djelic@parrot.com> Reviewed-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Dirk Behme <dirk.behme@gmail.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> (cherry picked from commit 455bd4c)

Zhouping Liu reported the following against 3.8-rc1 when running a mmap testcase from LTP. mapcount 0 page_mapcount 3 ------------[ cut here ]------------ kernel BUG at mm/huge_memory.c:1798! invalid opcode: 0000 [#1] SMP Modules linked in: ip6table_filter ip6_tables ebtable_nat ebtables bnep bluetooth rfkill iptable_mangle ipt_REJECT nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack iptable_filter ip_tables be2iscsi iscsi_boot_sysfs bnx2i cnic uio cxgb4i cxgb4 cxgb3i cxgb3 mdio libcxgbi ib_iser rdma_cm ib_addr iw_cm ib_cm ib_sa ib_mad ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi vfat fat dm_mirror dm_region_hash dm_log dm_mod cdc_ether iTCO_wdt i7core_edac coretemp usbnet iTCO_vendor_support mii crc32c_intel edac_core lpc_ich shpchp ioatdma mfd_core i2c_i801 pcspkr serio_raw bnx2 microcode dca vhost_net tun macvtap macvlan kvm_intel kvm uinput mgag200 sr_mod cdrom i2c_algo_bit sd_mod drm_kms_helper crc_t10dif ata_generic pata_acpi ttm ata_piix drm libata i2c_core megaraid_sas CPU 1 Pid: 23217, comm: mmap10 Not tainted 3.8.0-rc1mainline+ imx6-dongle#17 IBM IBM System x3400 M3 Server -[7379I08]-/69Y4356 RIP: __split_huge_page+0x677/0x6d0 RSP: 0000:ffff88017a03fc08 EFLAGS: 00010293 RAX: 0000000000000003 RBX: ffff88027a6c22e0 RCX: 00000000000034d2 RDX: 000000000000748b RSI: 0000000000000046 RDI: 0000000000000246 RBP: ffff88017a03fcb8 R08: ffffffff819d2440 R09: 000000000000054a R10: 0000000000aaaaaa R11: 00000000ffffffff R12: 0000000000000000 R13: 00007f4f11a00000 R14: ffff880179e96e00 R15: ffffea0005c08000 FS: 00007f4f11f4a740(0000) GS:ffff88017bc20000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 00000037e9ebb404 CR3: 000000017a436000 CR4: 00000000000007e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process mmap10 (pid: 23217, threadinfo ffff88017a03e000, task ffff880172dd32e0) Stack: ffff88017a540ec8 ffff88017a03fc20 ffffffff816017b5 ffff88017a03fc88 ffffffff812fa014 0000000000000000 ffff880279ebd5c0 00000000f4f11a4c 00000007f4f11f49 00000007f4f11a00 ffff88017a540ef0 ffff88017a540ee8 Call Trace: split_huge_page+0x68/0xb0 __split_huge_page_pmd+0x134/0x330 split_huge_page_pmd_mm+0x51/0x60 split_huge_page_address+0x3b/0x50 __vma_adjust_trans_huge+0x9c/0xf0 vma_adjust+0x684/0x750 __split_vma.isra.28+0x1fa/0x220 do_munmap+0xf9/0x420 vm_munmap+0x4e/0x70 sys_munmap+0x2b/0x40 system_call_fastpath+0x16/0x1b Alexander Beregalov and Alex Xu reported similar bugs and Hillf Danton identified that commit 5a50508 ("mm/rmap: Convert the struct anon_vma::mutex to an rwsem") and commit 4fc3f1d ("mm/rmap, migration: Make rmap_walk_anon() and try_to_unmap_anon() more scalable") were likely the problem. Reverting these commits was reported to solve the problem for Alexander. Despite the reason for these commits, NUMA balancing is not the direct source of the problem. split_huge_page() expects the anon_vma lock to be exclusive to serialise the whole split operation. Ordinarily it is expected that the anon_vma lock would only be required when updating the avcs but THP also uses the anon_vma rwsem for collapse and split operations where the page lock or compound lock cannot be used (as the page is changing from base to THP or vice versa) and the page table locks are insufficient. This patch takes the anon_vma lock for write to serialise against parallel split_huge_page as THP expected before the conversion to rwsem. Reported-and-tested-by: Zhouping Liu <zliu@redhat.com> Reported-by: Alexander Beregalov <a.beregalov@gmail.com> Reported-by: Alex Xu <alex_y_xu@yahoo.ca> Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

…optimizations Recent GCC versions (e.g. GCC-4.7.2) perform optimizations based on assumptions about the implementation of memset and similar functions. The current ARM optimized memset code does not return the value of its first argument, as is usually expected from standard implementations. For instance in the following function: void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter) { memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter)); waiter->magic = waiter; INIT_LIST_HEAD(&waiter->list); } compiled as: 800554d0 <debug_mutex_lock_common>: 800554d0: e92d4008 push {r3, lr} 800554d4: e1a00001 mov r0, r1 800554d8: e3a02010 mov r2, imx6-dongle#16 ; 0x10 800554dc: e3a01011 mov r1, imx6-dongle#17 ; 0x11 800554e0: eb04426e bl 80165ea0 <memset> 800554e4: e1a03000 mov r3, r0 800554e8: e583000c str r0, [r3, imx6-dongle#12] 800554ec: e5830000 str r0, [r3] 800554f0: e5830004 str r0, [r3, imx6-dongle#4] 800554f4: e8bd8008 pop {r3, pc} GCC assumes memset returns the value of pointer 'waiter' in register r0; causing register/memory corruptions. This patch fixes the return value of the assembly version of memset. It adds a 'mov' instruction and merges an additional load+store into existing load/store instructions. For ease of review, here is a breakdown of the patch into 4 simple steps: Step 1 ====== Perform the following substitutions: ip -> r8, then r0 -> ip, and insert 'mov ip, r0' as the first statement of the function. At this point, we have a memset() implementation returning the proper result, but corrupting r8 on some paths (the ones that were using ip). Step 2 ====== Make sure r8 is saved and restored when (! CALGN(1)+0) == 1: save r8: - str lr, [sp, #-4]! + stmfd sp!, {r8, lr} and restore r8 on both exit paths: - ldmeqfd sp!, {pc} @ Now <64 bytes to go. + ldmeqfd sp!, {r8, pc} @ Now <64 bytes to go. (...) tst r2, imx6-dongle#16 stmneia ip!, {r1, r3, r8, lr} - ldr lr, [sp], imx6-dongle#4 + ldmfd sp!, {r8, lr} Step 3 ====== Make sure r8 is saved and restored when (! CALGN(1)+0) == 0: save r8: - stmfd sp!, {r4-r7, lr} + stmfd sp!, {r4-r8, lr} and restore r8 on both exit paths: bgt 3b - ldmeqfd sp!, {r4-r7, pc} + ldmeqfd sp!, {r4-r8, pc} (...) tst r2, imx6-dongle#16 stmneia ip!, {r4-r7} - ldmfd sp!, {r4-r7, lr} + ldmfd sp!, {r4-r8, lr} Step 4 ====== Rewrite register list "r4-r7, r8" as "r4-r8". Signed-off-by: Ivan Djelic <ivan.djelic@parrot.com> Reviewed-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Dirk Behme <dirk.behme@gmail.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

do_loopback calls lock_mount(path) and forget to unlock_mount if clone_mnt or copy_mnt fails. [ 77.661566] ================================================ [ 77.662939] [ BUG: lock held when returning to user space! ] [ 77.664104] 3.9.0-rc5+ imx6-dongle#17 Not tainted [ 77.664982] ------------------------------------------------ [ 77.666488] mount/514 is leaving the kernel with locks still held! [ 77.668027] 2 locks held by mount/514: [ 77.668817] #0: (&sb->s_type->i_mutex_key#7){+.+.+.}, at: [<ffffffff811cca22>] lock_mount+0x32/0xe0 [ 77.671755] #1: (&namespace_sem){+++++.}, at: [<ffffffff811cca3a>] lock_mount+0x4a/0xe0 Signed-off-by: Andrey Vagin <avagin@openvz.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

…s struct file commit e4daf1ffbe6cc3b12aab4d604e627829e93e9914 upstream. The following call chain: ------------------------------------------------------------ nfs4_get_vfs_file - nfsd_open - dentry_open - do_dentry_open - __get_file_write_access - get_write_access - return atomic_inc_unless_negative(&inode->i_writecount) ? 0 : -ETXTBSY; ------------------------------------------------------------ can result in the following state: ------------------------------------------------------------ struct nfs4_file { ... fi_fds = {0xffff880c1fa65c80, 0xffffffffffffffe6, 0x0}, fi_access = {{ counter = 0x1 }, { counter = 0x0 }}, ... ------------------------------------------------------------ 1) First time around, in nfs4_get_vfs_file() fp->fi_fds[O_WRONLY] is NULL, hence nfsd_open() is called where we get status set to an error and fp->fi_fds[O_WRONLY] to -ETXTBSY. Thus we do not reach nfs4_file_get_access() and fi_access[O_WRONLY] is not incremented. 2) Second time around, in nfs4_get_vfs_file() fp->fi_fds[O_WRONLY] is NOT NULL (-ETXTBSY), so nfsd_open() is NOT called, but nfs4_file_get_access() IS called and fi_access[O_WRONLY] is incremented. Thus we leave a landmine in the form of the nfs4_file data structure in an incorrect state. 3) Eventually, when __nfs4_file_put_access() is called it finds fi_access[O_WRONLY] being non-zero, it decrements it and calls nfs4_file_put_fd() which tries to fput -ETXTBSY. ------------------------------------------------------------ ... [exception RIP: fput+0x9] RIP: ffffffff81177fa9 RSP: ffff88062e365c90 RFLAGS: 00010282 RAX: ffff880c2b3d99cc RBX: ffff880c2b3d9978 RCX: 0000000000000002 RDX: dead000000100101 RSI: 0000000000000001 RDI: ffffffffffffffe6 RBP: ffff88062e365c90 R8: ffff88041fe797d8 R9: ffff88062e365d58 R10: 0000000000000008 R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000007 R14: 0000000000000000 R15: 0000000000000000 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 imx6-dongle#9 [ffff88062e365c98] __nfs4_file_put_access at ffffffffa0562334 [nfsd] imx6-dongle#10 [ffff88062e365cc8] nfs4_file_put_access at ffffffffa05623ab [nfsd] imx6-dongle#11 [ffff88062e365ce8] free_generic_stateid at ffffffffa056634d [nfsd] imx6-dongle#12 [ffff88062e365d18] release_open_stateid at ffffffffa0566e4b [nfsd] imx6-dongle#13 [ffff88062e365d38] nfsd4_close at ffffffffa0567401 [nfsd] imx6-dongle#14 [ffff88062e365d88] nfsd4_proc_compound at ffffffffa0557f28 [nfsd] imx6-dongle#15 [ffff88062e365dd8] nfsd_dispatch at ffffffffa054543e [nfsd] imx6-dongle#16 [ffff88062e365e18] svc_process_common at ffffffffa04ba5a4 [sunrpc] imx6-dongle#17 [ffff88062e365e98] svc_process at ffffffffa04babe0 [sunrpc] imx6-dongle#18 [ffff88062e365eb8] nfsd at ffffffffa0545b62 [nfsd] imx6-dongle#19 [ffff88062e365ee8] kthread at ffffffff81090886 #20 [ffff88062e365f48] kernel_thread at ffffffff8100c14a ------------------------------------------------------------ Signed-off-by: Harshula Jayasuriya <harshula@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Frequency scaling not working. #17

Frequency scaling not working. #17

zakwiggy commented Sep 28, 2013

Frequency scaling not working. #17

Frequency scaling not working. #17

Comments

zakwiggy commented Sep 28, 2013