[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH 2 of 3] Make p2m lookups fully synchronized wrt modifications
> At 08:41 -0800 on 24 Nov (1322124101), Andres Lagar-Cavilla wrote: >> Here is one solution to consider: do not lock the p2m on lookups in >> shadow >> mode. Shadow mode does not support paging out and sharing of pages, >> which >> are primary reasons why we want synchronized p2m lookups. The hap cases >> where there is an inversion of the p2m_lock -> paging_lock order are >> reasonably simple to handle. >> >> The other option is to invert the order and place paging_lock -> >> p2m_lock, >> but that will raise another set of potential inversions. I think this is >> a >> no go. > > Is there scope for having the p2m lock split out into the overall one > (needed for allocations &c) and the per-record ones, and have them at > different levels in the lock hierarchy? I think it's saner to go with one big lock and then shard it if we run into performance problems. Your proposal, actually :) Now, I'm thinking of splitting ... the paging lock. It covers way too much ground right now, and many of these inversions would become more tractable. Thinking of paging_alloc_lock, paging_logdirty_lock, paging_lock. Thanks, Andres > > Tim. > _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel
|
![]() |
Lists.xenproject.org is hosted with RackSpace, monitoring our |