Am 14.06.2018 um 15:19 hat Denis V. Lunev geschrieben: > On 06/14/2018 04:16 PM, Kevin Wolf wrote: > > Am 08.06.2018 um 21:20 hat Vladimir Sementsov-Ogievskiy geschrieben: > >> Do data compression in separate threads. This significantly improve > >> performance for qemu-img convert with -W (allow async writes) and -c > >> (compressed) options. > >> > >> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com> > > Looks correct to me, but why do we introduce a separate > > MAX_COMPRESS_THREADS? Can't we simply leave the maximum number of > > threads to the thread poll? > > > > I see that you chose a much smaller number here (4 vs. 64), but is there > > actually a good reason for this? > > > > Kevin > yes. In the other case the guest will suffer much more from this increased > activity and load on the host.
Ah, your primary motivation is use in a backup block job? I completely forgot about that one (and qemu-img shouldn't care because there is no guest), but that makes some sense. Makes me wonder whether this value should be configurable. But that can come later. Kevin