[win-pv-devel] Very slow shared memory (gnttab)

[Martin Cerveny <martin@xxxxxxxxx>]

Hello.

I am facing very slow sharable memory (memcpy()) from Windows Guest (linux 
guests are Ok).
- write to sharable memory ~ 2MB/s (NOT GB)
- read from sharable memory ~ 4MB/s (NOT GB)
- r/w from/to local memory ~ > 8GB/s

- Dom0 shared 2048 refs (8MB RAM) (xc_gntshr_share_pages())
- window7 x64 imported (IOCTL_XENIFACE_GNTTAB_MAP_FOREIGN_PAGES)
- memcpy() to copy ~ 2MB data

- XenIface 8.2.0.51 (12.8.2016)
- XenBus 8.2.0.125 (21.9.2016)
- Windows 7SP1 + all patches
- VS2013
- Xen4.5.3, Xen4.6.1, Xen4.7.0
- Dom0 kernel XenServer kernel-3.10.41-332.380424 or kernel-3.10.96-484.383030

What is wrong ?
Are there any tunables ?

Thanks for answer, Martin Cerveny

_______________________________________________
win-pv-devel mailing list
win-pv-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/cgi-bin/mailman/listinfo/win-pv-devel