Messages in this thread | | | Date | Wed, 7 Sep 2022 15:59:33 +0800 | Subject | Re: [PATCH v2 5/5] sched/fair: cleanup for SIS_PROP | From | Abel Wu <> |
| |
On 9/1/22 10:03 PM, Mel Gorman wrote: > On Thu, Sep 01, 2022 at 09:11:07PM +0800, Abel Wu wrote: >> The sched-domain of this cpu is only used when SIS_PROP is enabled, >> and it should be irrelevant whether the local sd_llc is valid or >> not, since all we care about is target sd_llc if !SIS_PROP. >> >> Signed-off-by: Abel Wu <wuyun.abel@bytedance.com> > > This could conceivably result in an uninitialised memory access if > SIS_PROP was enabled while select_idle_cpu is running. I'm not sure if > it can happen when jump labels are in use but I think it could happen > for !CONFIG_JUMP_LABEL updating the sysctl_sched_features bitmap updated > via sysctl. > > The patch is still a good idea because it moves an unlikely rcu_deference > out of the default path for sched features but either this_sd needs to > be initialised to NULL and checked or the this_sd lookup needs to happen > twice at a slight additional cost to the default-disabled SIS_PROP path. >
Hi Mel, please check the following resent patch, Thanks!
https://lore.kernel.org/lkml/20220902033032.79846-5-wuyun.abel@bytedance.com/
| |