| Message ID | 20180516162829.14348-12-james.morse@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
> > arm64 can take an NMI-like error notification when user-space steps in some corrupt memory. APEI's GHES code will call > memory_failure_queue() to schedule the recovery work. We then return to user-space, possibly taking the fault again. > > Currently the arch code unconditionally signals user-space from this path, so we don't get stuck in this loop, but the affected process never > benefits from memory_failure()s recovery work. To fix this we need to know the recovery work will run before we get back to user-space. > > Increase the priority of the recovery work by scheduling it on the system_highpri_wq, then try to bump the current task off this CPU so that > the recover work starts immediately. > > Reported-by: Xie XiuQi <xiexiuqi@huawei.com> > Signed-off-by: James Morse <james.morse@arm.com> > Reviewed-by: Punit Agrawal <punit.agrawal@arm.com> > Tested-by: Tyler Baicar <tbaicar@codeaurora.org> > CC: Xie XiuQi <xiexiuqi@huawei.com> > CC: gengdongjiu <gengdongjiu@huawei.com> Tested-by: gengdongjiu <gengdongjiu@huawei.com> > --- > mm/memory-failure.c | 11 ++++++++--- > 1 file changed, 8 insertions(+), 3 deletions(-) > > diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 9d142b9b86dc..f0e69d7ac406 100644 > --- a/mm/memory-failure.c > +++ b/mm/memory-failure.c > @@ -55,6 +55,7 @@ > #include <linux/hugetlb.h> > #include <linux/memory_hotplug.h> > #include <linux/mm_inline.h> > +#include <linux/preempt.h> > #include <linux/kfifo.h> > #include <linux/ratelimit.h> > #include "internal.h" > @@ -1333,6 +1334,7 @@ static DEFINE_PER_CPU(struct memory_failure_cpu, memory_failure_cpu); > */ > void memory_failure_queue(unsigned long pfn, int flags) { > + int cpu = smp_processor_id(); > struct memory_failure_cpu *mf_cpu; > unsigned long proc_flags; > struct memory_failure_entry entry = { > @@ -1342,11 +1344,14 @@ void memory_failure_queue(unsigned long pfn, int flags) > > mf_cpu = &get_cpu_var(memory_failure_cpu); > spin_lock_irqsave(&mf_cpu->lock, proc_flags); > - if (kfifo_put(&mf_cpu->fifo, entry)) > - schedule_work_on(smp_processor_id(), &mf_cpu->work); > - else > + if (kfifo_put(&mf_cpu->fifo, entry)) { > + queue_work_on(cpu, system_highpri_wq, &mf_cpu->work); > + set_tsk_need_resched(current); > + preempt_set_need_resched(); > + } else { > pr_err("Memory failure: buffer overflow when queuing memory failure at %#lx\n", > pfn); > + } > spin_unlock_irqrestore(&mf_cpu->lock, proc_flags); > put_cpu_var(memory_failure_cpu); > } > -- > 2.16.2
> > arm64 can take an NMI-like error notification when user-space steps in some corrupt memory. APEI's GHES code will call > memory_failure_queue() to schedule the recovery work. We then return to user-space, possibly taking the fault again. > > Currently the arch code unconditionally signals user-space from this path, so we don't get stuck in this loop, but the affected process never > benefits from memory_failure()s recovery work. To fix this we need to know the recovery work will run before we get back to user-space. > > Increase the priority of the recovery work by scheduling it on the system_highpri_wq, then try to bump the current task off this CPU so that > the recover work starts immediately. > > Reported-by: Xie XiuQi <xiexiuqi@huawei.com> > Signed-off-by: James Morse <james.morse@arm.com> > Reviewed-by: Punit Agrawal <punit.agrawal@arm.com> > Tested-by: Tyler Baicar <tbaicar@codeaurora.org> > CC: Xie XiuQi <xiexiuqi@huawei.com> > CC: gengdongjiu <gengdongjiu@huawei.com> Tested-by: gengdongjiu <gengdongjiu@huawei.com> > --- > mm/memory-failure.c | 11 ++++++++--- > 1 file changed, 8 insertions(+), 3 deletions(-) > > diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 9d142b9b86dc..f0e69d7ac406 100644 > --- a/mm/memory-failure.c > +++ b/mm/memory-failure.c > @@ -55,6 +55,7 @@ > #include <linux/hugetlb.h> > #include <linux/memory_hotplug.h> > #include <linux/mm_inline.h> > +#include <linux/preempt.h> > #include <linux/kfifo.h> > #include <linux/ratelimit.h> > #include "internal.h" > @@ -1333,6 +1334,7 @@ static DEFINE_PER_CPU(struct memory_failure_cpu, memory_failure_cpu); > */ > void memory_failure_queue(unsigned long pfn, int flags) { > + int cpu = smp_processor_id(); > struct memory_failure_cpu *mf_cpu; > unsigned long proc_flags; > struct memory_failure_entry entry = { > @@ -1342,11 +1344,14 @@ void memory_failure_queue(unsigned long pfn, int flags) > > mf_cpu = &get_cpu_var(memory_failure_cpu); > spin_lock_irqsave(&mf_cpu->lock, proc_flags); > - if (kfifo_put(&mf_cpu->fifo, entry)) > - schedule_work_on(smp_processor_id(), &mf_cpu->work); > - else > + if (kfifo_put(&mf_cpu->fifo, entry)) { > + queue_work_on(cpu, system_highpri_wq, &mf_cpu->work); > + set_tsk_need_resched(current); > + preempt_set_need_resched(); > + } else { > pr_err("Memory failure: buffer overflow when queuing memory failure at %#lx\n", > pfn); > + } > spin_unlock_irqrestore(&mf_cpu->lock, proc_flags); > put_cpu_var(memory_failure_cpu); > } > -- > 2.16.2
diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 9d142b9b86dc..f0e69d7ac406 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -55,6 +55,7 @@ #include <linux/hugetlb.h> #include <linux/memory_hotplug.h> #include <linux/mm_inline.h> +#include <linux/preempt.h> #include <linux/kfifo.h> #include <linux/ratelimit.h> #include "internal.h" @@ -1333,6 +1334,7 @@ static DEFINE_PER_CPU(struct memory_failure_cpu, memory_failure_cpu); */ void memory_failure_queue(unsigned long pfn, int flags) { + int cpu = smp_processor_id(); struct memory_failure_cpu *mf_cpu; unsigned long proc_flags; struct memory_failure_entry entry = { @@ -1342,11 +1344,14 @@ void memory_failure_queue(unsigned long pfn, int flags) mf_cpu = &get_cpu_var(memory_failure_cpu); spin_lock_irqsave(&mf_cpu->lock, proc_flags); - if (kfifo_put(&mf_cpu->fifo, entry)) - schedule_work_on(smp_processor_id(), &mf_cpu->work); - else + if (kfifo_put(&mf_cpu->fifo, entry)) { + queue_work_on(cpu, system_highpri_wq, &mf_cpu->work); + set_tsk_need_resched(current); + preempt_set_need_resched(); + } else { pr_err("Memory failure: buffer overflow when queuing memory failure at %#lx\n", pfn); + } spin_unlock_irqrestore(&mf_cpu->lock, proc_flags); put_cpu_var(memory_failure_cpu); }