Messages in this thread | | | Subject | Re: [PATCH 1/1] arm64: kexec: machine_kexec should call __flush_icache_range | From | Dave Kleikamp <> | Date | Mon, 30 Jul 2018 11:46:24 -0500 |
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On 07/30/2018 11:22 AM, Will Deacon wrote: > On Mon, Jul 30, 2018 at 05:16:42PM +0100, Catalin Marinas wrote: >> On Mon, Jul 30, 2018 at 10:29:21AM -0500, Dave Kleikamp wrote: >>> machine_kexec flushes the reboot_code_buffer from the icache >>> after stopping the other cpus. >>> >>> Commit 3b8c9f1cdfc5 ("arm64: IPI each CPU after invalidating the I-cache >>> for kernel mappings") added an IPI call to flush_icache_range, which >>> causes a hang here, so replace the call with __flush_icache_range >> >> While machine_kexec() may be called with interrupts disabled (IIUC) and >> we shouldn't IPI other CPUs, I don't understand why it hangs here. Are >> there any other CPUs online at this point? > > The BUG_ON and WARN_ON at the start of machine_kexec() suggest to me that > this should only happen if we're kexec'ing a crash kernel and > smp_crash_stop_failed(). Is that something we need to care about?
I observed the hang trying to kexec a crash kernel and I did not see the warning that smp_crash_stop_failed(). I'm not exactly sure why flush_icache_range() hung (but it did), but I think that __flush_icache_range() makes more sense here anyway.
> > Will > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >
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