(2010/11/22 14:40), Takuya Yoshikawa wrote:
Hi,
I updated my patch set with your comments reflected.
Changelog:
- used enum
- lpage_idx issues
- function names
- measurements
- [PATCH 1/4] KVM: fix race condition in kvm_mmu_slot_remove_write_access()
- [PATCH 2/4] KVM: introduce helper to access lpage_info
- [PATCH 3/4] KVM: count the number of dirty pages for each memslot
- [RFC PATCH 4/4] KVM: selective write protection using dirty bitmap
The first one is a small fix and maybe worth applying seperately.
The second and third are preparation for the last one, but I believe
each has its own value.
I measured the time consumed by kvm_mmu_slot_remove_write_access[_mask]()
to decide at which conditions we choose *_mask(). Please check below!
* I implemented dirty_level_memslot() based on these results.
See [PATCH 4]
Is it possible to apply [PATCH 1 and 2] first?
It will help me a lot to concentrate on the main part.
Takuya
===
Test
- On core 2 duo machine (without EPT)
=> just because there was already test environment.
- 1GB RAM for the guest
- Workloads:
x11perf for frame buffer test
"find /" loop for live-migration test
- Time was measured by rdtscll
kvm mask: our method
kvm orig: original method
a) Frame buffer
---------------------------------------------------------------
kernel: [ 5584.954209] kvm: nr_dirty_pages/npages = 8/4096
kernel: [ 5584.954240] kvm mask: time(tsc) = 9485
kernel: [ 5992.185125] kvm: nr_dirty_pages/npages = 7/4096
kernel: [ 5992.185389] kvm orig: time(tsc) = 444724
45 times faster
---------------------------------------------------------------
kernel: [ 5588.330585] kvm: nr_dirty_pages/npages = 80/4096
kernel: [ 5588.330623] kvm mask: time(tsc) = 16688
kernel: [ 5996.183982] kvm: nr_dirty_pages/npages = 80/4096
kernel: [ 5996.184275] kvm orig: time(tsc) = 495551
30 times faster
---------------------------------------------------------------
kernel: [ 5578.156641] kvm: nr_dirty_pages/npages = 195/4096
kernel: [ 5578.156690] kvm mask: time(tsc) = 27335
kernel: [ 5985.109688] kvm: nr_dirty_pages/npages = 195/4096
kernel: [ 5985.109820] kvm orig: time(tsc) = 194530
7 times faster
---------------------------------------------------------------
kernel: [ 5605.821017] kvm: nr_dirty_pages/npages = 375/4096
kernel: [ 5605.821077] kvm mask: time(tsc) = 35049
kernel: [ 6014.627767] kvm: nr_dirty_pages/npages = 375/4096
kernel: [ 6014.628190] kvm orig: time(tsc) = 702737
20 times faster
---------------------------------------------------------------
kernel: [ 5573.551459] kvm: nr_dirty_pages/npages = 576/4096
kernel: [ 5573.551532] kvm mask: time(tsc) = 46718
kernel: [ 5981.486862] kvm: nr_dirty_pages/npages = 576/4096
kernel: [ 5981.487036] kvm orig: time(tsc) = 210385
5 times faster
---------------------------------------------------------------
b) Live-migration (1GB RAM)
---------------------------------------------------------------
kernel: [ 5011.599573] kvm: nr_dirty_pages/npages = 52/261888
kernel: [ 5011.599624] kvm mask: time(tsc) = 33712
kernel: [ 4297.465401] kvm: nr_dirty_pages/npages = 50/261888
kernel: [ 4297.465918] kvm orig: time(tsc) = 894593
25 times faster
---------------------------------------------------------------
kernel: [ 5009.045842] kvm: nr_dirty_pages/npages = 120/261888
kernel: [ 5009.045940] kvm mask: time(tsc) = 50575
kernel: [ 4295.438092] kvm: nr_dirty_pages/npages = 106/261888
kernel: [ 4295.438427] kvm orig: time(tsc) = 525140
10 times faster
---------------------------------------------------------------
kernel: [ 5016.914031] kvm: nr_dirty_pages/npages = 251/261888
kernel: [ 5016.914160] kvm mask: time(tsc) = 78750
kernel: [ 4297.265937] kvm: nr_dirty_pages/npages = 260/261888
kernel: [ 4297.266411] kvm orig: time(tsc) = 782446
10 times faster
---------------------------------------------------------------
kernel: [ 5015.717535] kvm: nr_dirty_pages/npages = 526/261888
kernel: [ 5015.717697] kvm mask: time(tsc) = 130137
kernel: [ 4295.370101] kvm: nr_dirty_pages/npages = 596/261888
kernel: [ 4295.370589] kvm orig: time(tsc) = 644805
5 times faster
---------------------------------------------------------------
kernel: [ 5011.693010] kvm: nr_dirty_pages/npages = 1029/261888
kernel: [ 5011.693177] kvm mask: time(tsc) = 219863
kernel: [ 4295.760635] kvm: nr_dirty_pages/npages = 1025/261888
kernel: [ 4295.761078] kvm orig: time(tsc) = 767333
3 times faster
---------------------------------------------------------------
kernel: [ 5014.805403] kvm: nr_dirty_pages/npages = 2219/261888
kernel: [ 5014.805676] kvm mask: time(tsc) = 454314
kernel: [ 4302.186712] kvm: nr_dirty_pages/npages = 1982/261888
kernel: [ 4302.191418] kvm orig: time(tsc) = 2294187
5 times faster
---------------------------------------------------------------
kernel: [ 5015.305794] kvm: nr_dirty_pages/npages = 4143/261888
kernel: [ 5015.306291] kvm mask: time(tsc) = 847175
kernel: [ 4302.068376] kvm: nr_dirty_pages/npages = 3835/261888
kernel: [ 4302.069456] kvm orig: time(tsc) = 1855105
3 times faster
---------------------------------------------------------------
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
