On Mon, Oct 14, 2013 at 5:45 PM, Saso Kiselkov <[email protected]>wrote:
> In that > the case, however, I have to ask why the original author put the retry > mechanism in with the pressure valve (halving the memory request size > each iteration) in the first place... > > I think I wrote that code a decade ago... The idea was probably that there might not be enough physical memory free -- nothing about fragmentation. This was back when you could boot off of UFS and then load the zfs kernel module later (frequently used while debugging). But I'm not sure that the retry was ever exercised. I can't imagine it has been used in the past 5 years since (AFAIK) solaris & illumos distros only boot from ZFS. Linux (and FreeBSD?) may be a different matter. Since the zfs kernel module can be loaded much after boot, there may be insufficient memory. Don't know how likely that is, though. Nor do I know how memory fragmentation (virtual or physical) might come into play on those platforms. --matt
_______________________________________________ developer mailing list [email protected] http://lists.open-zfs.org/mailman/listinfo/developer
