# git rev-parse -q --verify daebe06ec4af252eba275f602a08086bc2bca5dc^{commit}
# git fetch -q -n -f git://gitlab.ozlabs.ibm.com/linuxppc/linux.git fixes-test
# git rev-parse -q --verify daebe06ec4af252eba275f602a08086bc2bca5dc^{commit}
daebe06ec4af252eba275f602a08086bc2bca5dc
# git checkout -q -f -B kisskb daebe06ec4af252eba275f602a08086bc2bca5dc
# git clean -qxdf
# < git log -1
# commit daebe06ec4af252eba275f602a08086bc2bca5dc
# Author: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
# Date:   Wed Apr 25 16:29:31 2018 +0530
# 
#     cpufreq: powernv: Fix the hardlockup by synchronus smp_call in timer interrupt
#     
#     gpstate_timer_handler() uses synchronous smp_call to set the pstate
#     on the requested core. This causes the below hard lockup:
#     
#       smp_call_function_single+0x110/0x180 (unreliable)
#       smp_call_function_any+0x180/0x250
#       gpstate_timer_handler+0x1e8/0x580
#       call_timer_fn+0x50/0x1c0
#       expire_timers+0x138/0x1f0
#       run_timer_softirq+0x1e8/0x270
#       __do_softirq+0x158/0x3e4
#       irq_exit+0xe8/0x120
#       timer_interrupt+0x9c/0xe0
#       decrementer_common+0x114/0x120
#       -- interrupt: 901 at doorbell_global_ipi+0x34/0x50
#       LR = arch_send_call_function_ipi_mask+0x120/0x130
#       arch_send_call_function_ipi_mask+0x4c/0x130
#       smp_call_function_many+0x340/0x450
#       pmdp_invalidate+0x98/0xe0
#       change_huge_pmd+0xe0/0x270
#       change_protection_range+0xb88/0xe40
#       mprotect_fixup+0x140/0x340
#       SyS_mprotect+0x1b4/0x350
#       system_call+0x58/0x6c
#     
#     One way to avoid this is removing the smp-call. We can ensure that the
#     timer always runs on one of the policy-cpus. If the timer gets
#     migrated to a cpu outside the policy then re-queue it back on the
#     policy->cpus. This way we can get rid of the smp-call which was being
#     used to set the pstate on the policy->cpus.
#     
#     Fixes: 7bc54b652f13 ("timers, cpufreq/powernv: Initialize the gpstate timer as pinned")
#     Cc: stable@vger.kernel.org # v4.8+
#     Reported-by: Nicholas Piggin <npiggin@gmail.com>
#     Reported-by: Pridhiviraj Paidipeddi <ppaidipe@linux.vnet.ibm.com>
#     Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
#     Acked-by: Nicholas Piggin <npiggin@gmail.com>
#     Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
#     Acked-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
#     Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
# < /opt/cross/kisskb/gcc-4.6.3-nolibc/m68k-linux/bin/m68k-linux-gcc --version
# < git log --format=%s --max-count=1 daebe06ec4af252eba275f602a08086bc2bca5dc
# < make -s -j 40 ARCH=m68k O=/kisskb/build/powerpc-fixes_m68k-defconfig_m68k CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/m68k-linux/bin/m68k-linux-  defconfig
arch/m68k/configs/multi_defconfig:108:warning: symbol value 'm' invalid for NF_TABLES_INET
arch/m68k/configs/multi_defconfig:109:warning: symbol value 'm' invalid for NF_TABLES_NETDEV
arch/m68k/configs/multi_defconfig:214:warning: symbol value 'm' invalid for NF_TABLES_ARP
arch/m68k/configs/multi_defconfig:269:warning: symbol value 'm' invalid for NF_TABLES_BRIDGE
# make -s -j 40 ARCH=m68k O=/kisskb/build/powerpc-fixes_m68k-defconfig_m68k CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/m68k-linux/bin/m68k-linux-  
<stdin>:1239:2: warning: #warning syscall seccomp not implemented [-Wcpp]
<stdin>:1317:2: warning: #warning syscall pkey_mprotect not implemented [-Wcpp]
<stdin>:1320:2: warning: #warning syscall pkey_alloc not implemented [-Wcpp]
<stdin>:1323:2: warning: #warning syscall pkey_free not implemented [-Wcpp]
/kisskb/src/arch/m68k/mvme147/config.c: In function 'mvme147_hwclk':
/kisskb/src/arch/m68k/mvme147/config.c:152:2: warning: #warning check me! [-Wcpp]
/kisskb/src/arch/m68k/mvme16x/config.c: In function 'mvme16x_hwclk':
/kisskb/src/arch/m68k/mvme16x/config.c:399:2: warning: #warning check me! [-Wcpp]
/kisskb/src/ipc/shm.c: In function 'ksys_shmdt':
/kisskb/src/ipc/shm.c:1637:59: warning: 'file' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/lib/mpi/mpicoder.c: In function 'mpi_read_raw_from_sgl':
/kisskb/src/lib/mpi/mpicoder.c:336:12: warning: 'buff' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/kernel/printk/printk.c: In function 'devkmsg_sysctl_set_loglvl':
/kisskb/src/kernel/printk/printk.c:183:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/net/core/gen_stats.c: In function '__gnet_stats_copy_basic':
/kisskb/src/net/core/gen_stats.c:149:19: warning: 'seq' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/net/core/flow_dissector.c: In function '__skb_flow_dissect':
/kisskb/src/net/core/flow_dissector.c:789:7: warning: 'vlan' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/net/core/dev.c: In function 'validate_xmit_skb_list':
/kisskb/src/net/core/dev.c:3176:15: warning: 'tail' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/fs/proc/inode.c: In function 'proc_reg_open':
/kisskb/src/include/linux/list.h:65:12: warning: 'pdeo' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/fs/proc/inode.c:340:21: note: 'pdeo' was declared here
/kisskb/src/kernel/acct.c: In function 'acct_pin_kill':
/kisskb/src/kernel/acct.c:177:2: warning: value computed is not used [-Wunused-value]
/kisskb/src/lib/rhashtable.c: In function 'rht_deferred_worker':
/kisskb/src/lib/rhashtable.c:269:2: warning: 'next' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/lib/rhashtable.c:234:28: note: 'next' was declared here
/kisskb/src/fs/udf/unicode.c: In function 'udf_name_conv_char':
/kisskb/src/fs/udf/unicode.c:163:15: warning: 'c' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/fs/ocfs2/file.c: In function 'ocfs2_file_write_iter':
/kisskb/src/fs/ocfs2/file.c:2386:3: warning: value computed is not used [-Wunused-value]
/kisskb/src/drivers/net/macsec.c: In function 'macsec_del_rxsa':
/kisskb/src/drivers/net/macsec.c:1926:2: warning: 'assoc_num' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/net/macsec.c:1926:2: warning: 'rx_sc' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/net/macsec.c: In function 'macsec_del_txsa':
/kisskb/src/drivers/net/macsec.c:2003:2: warning: 'assoc_num' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/net/macsec.c:2003:2: warning: 'tx_sc' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/net/macsec.c: In function 'macsec_upd_txsa':
/kisskb/src/drivers/net/macsec.c:2068:5: warning: 'assoc_num' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/net/macsec.c:2068:24: warning: 'tx_sc' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/net/macsec.c:2069:21: warning: 'secy' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/net/tun.c: In function 'tun_get_user':
/kisskb/src/drivers/net/tun.c:1822:30: warning: 'copylen' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/net/tun.c:1532:31: warning: 'linear' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/net/tun.c:1732:46: note: 'linear' was declared here
/kisskb/src/fs/posix_acl.c: In function 'get_acl':
/kisskb/src/fs/posix_acl.c:147:3: warning: value computed is not used [-Wunused-value]
Completed OK
# rm -rf /kisskb/build/powerpc-fixes_m68k-defconfig_m68k
# Build took: 0:01:18.163161