Messages in this thread | | | Date | Thu, 21 Aug 2008 15:16:52 +0200 | From | Robert Richter <> | Subject | Re: patch "x86: MOVE PCI IO ECS code to x86/pci" breaks CPU hotplug |
| |
On 21.08.08 15:02:59, Ingo Molnar wrote: > > * Jan Beulich <jbeulich@novell.com> wrote: > > > Converting __cpuinit functions called out of init_amd() (and similar > > others) to __init (and making them subject of xxx_initcall() handling > > isn't valid, as they would no longer be called for hot plugged CPUs. > > > > Further, since it's likely that in virtualized environments the MSR > > write would at best be ignored, I'd also recommend using the > > fault-safe accessors here *and* check that the bit actually got set > > before setting PCI_HAS_IO_ECS (one would obviously have to BUG() when > > hot-plugged CPUs fail to set the bit when those available at boot > > successfully did so). > > hm, which patch is this exactly, and in what tree? It's not upstream nor > in -tip.
Probably this in the mainline kernel is meant:
commit 3a27dd1ce5de08e21e0266ddf00e6f1f843bfe8b Author: Robert Richter <robert.richter@amd.com> Date: Thu Jun 12 20:19:23 2008 +0200
x86: Move PCI IO ECS code to x86/pci
"Form follows function". Code is now where it belongs to.
Signed-off-by: Robert Richter <robert.richter@amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
The problem is code like this:
+static int __init enable_pci_io_ecs(void) +{ + /* assume all cpus from fam10h have IO ECS */ + if (boot_cpu_data.x86 < 0x10) + return 0; + on_each_cpu(enable_pci_io_ecs_per_cpu, NULL, 1, 1); + pci_probe |= PCI_HAS_IO_ECS; + return 0; +}
It is only called during the setup and if the cpu is enabled. I intend to rewrite the cpu setup code using cpu notifiers.
-Robert
-- Advanced Micro Devices, Inc. Operating System Research Center email: robert.richter@amd.com
| |