blob: eb69fc5ecae6c0f60f07b06b7c8629802fa5a2b9 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
|
qemu is very slow when adding 16,384 virtio-scsi drives
qemu runs very slowly when adding many virtio-scsi drives. I have attached a small reproducer shell script which demonstrates this.
Using perf shows the following stack trace taking all the time:
72.42% 71.15% qemu-system-x86 qemu-system-x86_64 [.] drive_get
|
--72.32%--drive_get
|
--1.24%--__irqentry_text_start
|
--1.22%--smp_apic_timer_interrupt
|
--1.00%--local_apic_timer_interrupt
|
--1.00%--hrtimer_interrupt
|
--0.83%--__hrtimer_run_queues
|
--0.64%--tick_sched_timer
21.70% 21.34% qemu-system-x86 qemu-system-x86_64 [.] blk_legacy_dinfo
|
---blk_legacy_dinfo
3.65% 3.59% qemu-system-x86 qemu-system-x86_64 [.] blk_next
|
---blk_next
|