Messages in this thread | | | Date | Tue, 12 Dec 2006 14:57:05 -0800 (PST) | From | Linus Torvalds <> | Subject | Re: Mach-O binary format support and Darwin syscall personality [Was: uts banner changes] |
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On Wed, 13 Dec 2006, Benjamin Herrenschmidt wrote: > > > Secondly, is there a preferred existing field into which I should > > stick said flag or just stuff it somewhere? > > Yes, thread_info->flags.
Well, it may actually make sense to actually stick the whole "syscall table pointer" in there, rather than a flag that says which pointer to choose.
We already load the thread_info pointer because we need the flags for syscall tracing, and since we have the thread_info pointer, it might be easier to load the syscall table pointer right off there, rather than loading it as a big constant with "lis + ori" (in fact, on ppc64, we currently load it off the TOC, which is really sad, since we already brought in the thread_info into the cache, and usign the TOC is not just a load, it's a load off a separate cacheline).
So on 64-bit ppc, it could actually speed things up to put the system call table pointer into thread_info, and make it more flexible at the same time, without any conditional flags.
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