This is a note to let you know that I've just added the patch titled powerpc/perf: Remove PPMU_HAS_SSLOT flag for Power8 to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: powerpc-perf-remove-ppmu_has_sslot-flag-for-power8.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 370f06c88528b3988fe24a372c10e1303bb94cf6 Mon Sep 17 00:00:00 2001 From: Madhavan Srinivasan <maddy@xxxxxxxxxxxxxxxxxx> Date: Mon, 25 Jan 2016 14:03:46 +0530 Subject: powerpc/perf: Remove PPMU_HAS_SSLOT flag for Power8 From: Madhavan Srinivasan <maddy@xxxxxxxxxxxxxxxxxx> commit 370f06c88528b3988fe24a372c10e1303bb94cf6 upstream. Commit 7a7868326d77 ("powerpc/perf: Add an explict flag indicating presence of SLOT field") introduced the PPMU_HAS_SSLOT flag to remove the assumption that MMCRA[SLOT] was present when PPMU_ALT_SIPR was not set. That commit's changelog also mentions that Power8 does not support MMCRA[SLOT]. However when the Power8 PMU support was merged, it errnoeously included the PPMU_HAS_SSLOT flag. So remove PPMU_HAS_SSLOT from the Power8 flags. mpe: On systems where MMCRA[SLOT] exists, the field occupies bits 37:39 (IBM numbering). On Power8 bit 37 is reserved, and 38:39 overlap with the high bits of the Threshold Event Counter Mantissa. I am not aware of any published events which use the threshold counting mechanism, which would cause the mantissa bits to be set. So in practice this bug is unlikely to trigger. Fixes: e05b9b9e5c10 ("powerpc/perf: Power8 PMU support") Signed-off-by: Madhavan Srinivasan <maddy@xxxxxxxxxxxxxxxxxx> Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/powerpc/perf/power8-pmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/powerpc/perf/power8-pmu.c +++ b/arch/powerpc/perf/power8-pmu.c @@ -816,7 +816,7 @@ static struct power_pmu power8_pmu = { .get_constraint = power8_get_constraint, .get_alternatives = power8_get_alternatives, .disable_pmc = power8_disable_pmc, - .flags = PPMU_HAS_SSLOT | PPMU_HAS_SIER | PPMU_ARCH_207S, + .flags = PPMU_HAS_SIER | PPMU_ARCH_207S, .n_generic = ARRAY_SIZE(power8_generic_events), .generic_events = power8_generic_events, .cache_events = &power8_cache_events, Patches currently in stable-queue which might be from maddy@xxxxxxxxxxxxxxxxxx are queue-4.4/powerpc-perf-remove-ppmu_has_sslot-flag-for-power8.patch