Messages in this thread | | | Subject | Re: staging: ion: ION allocation fall back order depends on heap linkage order | From | Laura Abbott <> | Date | Wed, 7 Feb 2018 06:58:36 -0800 |
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On 02/06/2018 11:05 PM, Alexey Skidanov wrote: > > >> Yup, you've hit upon a key problem. Having fallbacks be stable >> was always a problem and the recommendation these days is to >> not rely on them. You can specify a heap at a time and fallback >> manually if you want that behavior. >> >> If you have a proposal to make fallbacks work reliably without >> overly complicating the ABI I'm happy to review it. >> >> Thanks, >> Laura >> > I think it's possible to "automate" the "manual fallback" behavior. But > the real issues is using heap id to specify the particular heap object. > > Current API (allocation IOCTL) requires to specify the particular heap > object by using heap id. From the other hand, the user space doesn't > control the heaps creation order and heap id assignment. So it may be > tricky, especially when more than one object of the same heap type is > created automatically. > > Thanks, > Alexey > >
The query ioctl is designed to get the heap ID information without needing to rely on the linking order or anything else defined in the kernel.
Thanks, Laura
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