From: Juergen Gross jgross@suse.com
stable inclusion from stable-v6.6.3 commit a7762cb2904603bf5e3001fa29f3ed6713b82daf category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I8LBQP
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ Upstream commit 47d970204054f859f35a2237baa75c2d84fcf436 ]
When delaying eoi handling of events, the related elements are queued into the percpu lateeoi list. In case the list isn't empty, the elements should be sorted by the time when eoi handling is to happen.
Unfortunately a new element will never be queued at the start of the list, even if it has a handling time lower than all other list elements.
Fix that by handling that case the same way as for an empty list.
Fixes: e99502f76271 ("xen/events: defer eoi in case of excessive number of events") Reported-by: Jan Beulich jbeulich@suse.com Signed-off-by: Juergen Gross jgross@suse.com Reviewed-by: Oleksandr Tyshchenko oleksandr_tyshchenko@epam.com Signed-off-by: Juergen Gross jgross@suse.com Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- drivers/xen/events/events_base.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c index 2cf0c2b69386..c50419638ac0 100644 --- a/drivers/xen/events/events_base.c +++ b/drivers/xen/events/events_base.c @@ -604,7 +604,9 @@ static void lateeoi_list_add(struct irq_info *info)
spin_lock_irqsave(&eoi->eoi_list_lock, flags);
- if (list_empty(&eoi->eoi_list)) { + elem = list_first_entry_or_null(&eoi->eoi_list, struct irq_info, + eoi_list); + if (!elem || info->eoi_time < elem->eoi_time) { list_add(&info->eoi_list, &eoi->eoi_list); mod_delayed_work_on(info->eoi_cpu, system_wq, &eoi->delayed, delay);