Hi Marc, Sumit I would appreciate if you have any advice on this patch.
Yuichi Ito > -----Original Message----- > From: Yuichi Ito <ito-yui...@fujitsu.com> > Sent: Thursday, September 24, 2020 1:43 PM > To: m...@kernel.org; sumit.g...@linaro.org; t...@linutronix.de; > ja...@lakedaemon.net; catalin.mari...@arm.com; w...@kernel.org > Cc: linux-arm-ker...@lists.infradead.org; linux-kernel@vger.kernel.org; Ito, > Yuichi/伊藤 有一 <ito-yui...@fujitsu.com> > Subject: [PATCH 0/2] Enable support IPI_CPU_CRASH_STOP to be > pseudo-NMI > > Enable support IPI_CPU_CRASH_STOP to be pseudo-NMI > > This patchset enables IPI_CPU_CRASH_STOP IPI to be pseudo-NMI. > This allows kdump to collect system information even when the CPU is in a > HARDLOCKUP state. > > Only IPI_CPU_CRASH_STOP uses NMI and the other IPIs remain normal > IRQs. > > The patch has been tested on ThunderX. > > This patch assumes Marc's latest IPIs patch-set. [1] It also uses some of > Sumit's IPI patch set for NMI.[2] > > [1] > https://lore.kernel.org/linux-arm-kernel/20200901144324.1071694-1-maz@ke > rnel.org/ > [2] > https://lore.kernel.org/linux-arm-kernel/1599830924-13990-3-git-send-email > -sumit.g...@linaro.org/ > > $ echo 1 > /proc/sys/kernel/panic_on_rcu_stal > $ echo HARDLOCKUP > /sys/kernel/debug/provoke-crash/DIRECT > : kernel panics and crash kernel boot > : makedumpfile saves the system state at HARDLOCKUP in vmcore. > > crash utility: > crash> bt > PID: 3213 TASK: fffffd001adc5940 CPU: 8 COMMAND: "bash" > #0 [fffffe0022fefcf0] lkdtm_HARDLOCKUP at fffffe0010888ab4 > #1 [fffffe0022fefd10] lkdtm_do_action at fffffe00108882bc > #2 [fffffe0022fefd20] direct_entry at fffffe0010888720 > #3 [fffffe0022fefd70] full_proxy_write at fffffe001058cfe4 > #4 [fffffe0022fefdb0] vfs_write at fffffe00104a4c2c > #5 [fffffe0022fefdf0] ksys_write at fffffe00104a4f0c > #6 [fffffe0022fefe40] __arm64_sys_write at fffffe00104a4fbc > #7 [fffffe0022fefe50] el0_svc_common.constprop.0 at fffffe0010159e38 > #8 [fffffe0022fefe80] do_el0_svc at fffffe0010159fa0 > #9 [fffffe0022fefe90] el0_svc at fffffe00101481d0 > #10 [fffffe0022fefea0] el0_sync_handler at fffffe00101484b4 > #11 [fffffe0022fefff0] el0_sync at fffffe0010142b7c > > > Sumit Garg (1): > irqchip/gic-v3: Enable support for SGIs to act as NMIs > > Yuichi Ito (1): > Register IPI_CPU_CRASH_STOP IPI as pseudo-NMI > > arch/arm64/kernel/smp.c | 39 > ++++++++++++++++++++++++++++-------- > drivers/irqchip/irq-gic-v3.c | 13 ++++++++++-- > 2 files changed, 42 insertions(+), 10 deletions(-) > > -- > 2.25.1