On 04/09/2013 11:10 PM, Colin Cross wrote: > On Tue, Apr 9, 2013 at 8:08 PM, Rob Herring <robherri...@gmail.com> wrote: >> From: Rob Herring <rob.herr...@calxeda.com> >> >> For persistent RAM outside of main memory, the memory may have limitations >> on supported accesses. For internal RAM on highbank platform exclusive >> accesses are not supported and will hang the system. So atomic_cmpxchg >> cannot be used. This commit uses spinlock protection for buffer size and >> start updates on ioremapped regions instead. > > I used atomics in persistent_ram to support persistent ftrace, which > now exists as PSTORE_FTRACE. At some point during development I had > trouble with recursive tracing causing an infinite loop, so you may > want to test that calling out to spinlock functions with PSTORE_FTRACE > turned on and enabled doesn't cause a problem.
I've tested that now and it appears to work fine. Was there some specific setup of ftrace that caused problems? Rob -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
