Messages in this thread | | | Date | Thu, 11 Apr 2024 15:13:20 +0100 | From | Dave Martin <> | Subject | Re: [PATCH v1 01/31] x86/resctrl: Fix allocation of cleanest CLOSID on platforms with no monitors |
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On Mon, Apr 08, 2024 at 08:13:40PM -0700, Reinette Chatre wrote: > Hi James, > > On 3/21/2024 9:50 AM, James Morse wrote: > > commit 6eac36bb9eb0 ("x86/resctrl: Allocate the cleanest CLOSID by > > searching closid_num_dirty_rmid") added a Kconfig option that causes > > Please see section about "Fixes" tags in section "Ordering of commit tags" > in Documentation/process/maintainer-tip.rst
Noted for James' attention.
> > resctrl to search for the CLOSID with the fewest dirty cache lines when > > creating a new control group. This depends on the values read from the > > llc_occupancy counters. > > > > This support missed that some platforms may not have these counters. > > This causes a NULL pointer dereference when creating a new control > > group as the array was not allocated by dom_data_init(). > > > > As this feature isn't necessary on platforms that don't have cache > > occupancy monitors, add this to the check that occurs when a new > > control group is allocated. > > > > The existing code is not selected by any upstream platform, it makes > > no sense to backport this patch to stable. > > > > Signed-off-by: James Morse <james.morse@arm.com> > > --- > > arch/x86/kernel/cpu/resctrl/rdtgroup.c | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c > > index 011e17efb1a6..1767c1affa60 100644 > > --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c > > +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c > > @@ -149,7 +149,8 @@ static int closid_alloc(void) > > > > lockdep_assert_held(&rdtgroup_mutex); > > > > - if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) { > > + if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID) && > > + is_llc_occupancy_enabled()) { > > cleanest_closid = resctrl_find_cleanest_closid(); > > if (cleanest_closid < 0) > > return cleanest_closid; > > Patch looks good. > > Thank you > > Reinette >
Noted, thanks.
Cheers ---Dave
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