* [Qemu-devel] coroutine pool memory usage
@ 2015-08-27 9:26 Peter Lieven
2015-08-27 15:23 ` Paolo Bonzini
0 siblings, 1 reply; 3+ messages in thread
From: Peter Lieven @ 2015-08-27 9:26 UTC (permalink / raw)
To: qemu block, qemu-devel@nongnu.org
Cc: Kevin Wolf, Paolo Bonzini, Stefan Hajnoczi
Hi,
i was debugging increased memory footprint of qemu over the past time and found that the coroutine
pool heap usage can grow up to 70MB by just booting an Ubuntu Live CD. And those 70MB are never
freed.
Is this expected? Wouldn't it make sense to asynchronically throw some coroutines (or at least their stack)
away if there is no I/O?
Does anyone have a pointer to benchmarks of coroutine performance for NAS (iSCSI / NFS) with and without
freelist? I would think that it only has significant impact for local (SSD) storage?
Thanks,
Peter
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [Qemu-devel] coroutine pool memory usage
2015-08-27 9:26 [Qemu-devel] coroutine pool memory usage Peter Lieven
@ 2015-08-27 15:23 ` Paolo Bonzini
2015-08-27 15:28 ` Peter Lieven
0 siblings, 1 reply; 3+ messages in thread
From: Paolo Bonzini @ 2015-08-27 15:23 UTC (permalink / raw)
To: Peter Lieven; +Cc: Kevin Wolf, Stefan Hajnoczi, qemu-devel, qemu block
> i was debugging increased memory footprint of qemu over the past time and
> found that the coroutine pool heap usage can grow up to 70MB by just booting
> an Ubuntu Live CD. And those 70MB are never freed.
>
> Is this expected? Wouldn't it make sense to asynchronically throw some
> coroutines (or at least their stack) away if there is no I/O?
Yes, perhaps that can be added. But is it RSS that increases, or is it just
wasted address space?
Paolo
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [Qemu-devel] coroutine pool memory usage
2015-08-27 15:23 ` Paolo Bonzini
@ 2015-08-27 15:28 ` Peter Lieven
0 siblings, 0 replies; 3+ messages in thread
From: Peter Lieven @ 2015-08-27 15:28 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: Kevin Wolf, Stefan Hajnoczi, qemu-devel, qemu block
Am 27.08.2015 um 17:23 schrieb Paolo Bonzini:
>> i was debugging increased memory footprint of qemu over the past time and
>> found that the coroutine pool heap usage can grow up to 70MB by just booting
>> an Ubuntu Live CD. And those 70MB are never freed.
>>
>> Is this expected? Wouldn't it make sense to asynchronically throw some
>> coroutines (or at least their stack) away if there is no I/O?
> Yes, perhaps that can be added. But is it RSS that increases, or is it just
> wasted address space?
Sorry, false alarm. I had a debugger running and in this case all memory
seems to be allocated. RSS is fine. I tracked the actual stack space that
is used to around 1400 Byte per coroutine. So no problem.
Peter
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2015-08-27 15:28 UTC | newest]
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2015-08-27 9:26 [Qemu-devel] coroutine pool memory usage Peter Lieven
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