From 128f3cb9398b5eeb4ee04b60bd5e314f5c122821 Mon Sep 17 00:00:00 2001 From: Chris Metcalf Date: Mon, 30 Mar 2015 16:33:00 -0400 Subject: tile: nohz: warn if nohz_full uses hypervisor shared cores The "hypervisor shared" cores are ones that the Tilera hypervisor uses to receive interrupts to manage hypervisor-owned devices. It's a bad idea to try to use those cores with nohz_full, since they will get interrupted unpredictably -- and invisibly to Linux tracing tools, since the interrupts are delivered at a higher privilege level to the Tilera hypervisor. Generate a clear warning at boot up that this doesn't end well for the nohz_full cores in question. Signed-off-by: Chris Metcalf --- arch/tile/include/hv/hypervisor.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'arch/tile/include') diff --git a/arch/tile/include/hv/hypervisor.h b/arch/tile/include/hv/hypervisor.h index dfcdeb61ba34..e0e6af4e783b 100644 --- a/arch/tile/include/hv/hypervisor.h +++ b/arch/tile/include/hv/hypervisor.h @@ -961,7 +961,11 @@ typedef enum { HV_INQ_TILES_HFH_CACHE = 2, /** The set of tiles that can be legally used as a LOTAR for a PTE. */ - HV_INQ_TILES_LOTAR = 3 + HV_INQ_TILES_LOTAR = 3, + + /** The set of "shared" driver tiles that the hypervisor may + * periodically interrupt. */ + HV_INQ_TILES_SHARED = 4 } HV_InqTileSet; /** Returns specific information about various sets of tiles within the -- cgit v1.2.3