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| author |   Christian Borntraeger <borntraeger@linux.ibm.com> | 2022-05-30 11:27:05 +0200 |
|---|---|---|
| committer |   Heiko Carstens <hca@linux.ibm.com> | 2022-06-01 12:03:16 +0200 |
| commit | 6d5946274df1fff539a7eece458a43be733d1db8 (patch) | |
| tree | e7d3215f840d3b1ffad53ba7ff186abe542ff12e /virt | |
| parent | MAINTAINERS: Update s390 virtio-ccw (diff) | |
| download | linux-dev-6d5946274df1fff539a7eece458a43be733d1db8.tar.xz linux-dev-6d5946274df1fff539a7eece458a43be733d1db8.zip | |
s390/gmap: voluntarily schedule during key setting
With large and many guest with storage keys it is possible to create
large latencies or stalls during initial key setting:
rcu: INFO: rcu_sched self-detected stall on CPU
rcu: 18-....: (2099 ticks this GP) idle=54e/1/0x4000000000000002 softirq=35598716/35598716 fqs=998
(t=2100 jiffies g=155867385 q=20879)
Task dump for CPU 18:
CPU 1/KVM R running task 0 1030947 256019 0x06000004
Call Trace:
sched_show_task
rcu_dump_cpu_stacks
rcu_sched_clock_irq
update_process_times
tick_sched_handle
tick_sched_timer
__hrtimer_run_queues
hrtimer_interrupt
do_IRQ
ext_int_handler
ptep_zap_key
The mmap lock is held during the page walking but since this is a
semaphore scheduling is still possible. Same for the kvm srcu.
To minimize overhead do this on every segment table entry or large page.
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Link: https://lore.kernel.org/r/20220530092706.11637-2-borntraeger@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Diffstat (limited to 'virt')
0 files changed, 0 insertions, 0 deletions