On Thu, Jan 12, 2012 at 3:17 AM, Milton Miller <milt...@bga.com> wrote: > On Wed Jan 11 2012 about 15:24:34 EST, Grant Likely wrote: >> There is only one user, and it is trivial to open-code. > > I added virq_is_host because I had planned to change how we find the > host (domain) from a virq. > > Instead of storing a pointer in irq_desc (a pointer for every irq), > I planned to use a NR_IRQ(+extra) bitmap per domain. This should be > a win storage-wise when the number of irq controllers is less than the > number of bits in a long. > > This would also convert scanning for a reverse map from walking every > irqdesc to walking find_next_bit over the irqs assigned to the host. > > Thus my rule was "code outside kernel/irq must not touch domain"; > both the contents and how it was associated were abstracted. > > Other planned changes included splitting the reverse lookup into > domain dependent pieces, creating the ida for sparse map at domain > creation time (init irq is after radix_tree_init as its used by the > current irq code) so we never fall back to linear search. Linear > populated the reverse map as the irq was assigned, and changed to > a seperate subtype if it mapped an irq above the map size. > > I thought some of the domains would be split into seperate files > selected by Kconfig, at least the sparse tree. > > There was also a nomap varient to handle iseries (and one of the cell > varients) where the interrupt number to use for an event is controlled > by the guest, that led to the discussion with tlgx about how to > disallow the extra irqs above the limit set by the arch callback. > > Actually making virq-is-domain a domain callback could eliminate the > need for the bitmap on legacy (range limited) domains. > > > I have my work in progress patches from 2.6.39 if you would like to > see them. I was trying to clean up powerpc before pushing it over, > and didn't get all the concepts written. So I just sent Ben what > was ready at the time and haven't had time to get back to it.
Go ahead and send me your patches. I'll see what I can add into my series. > Overall, I think most of the other concepts are ok, although I would > have chosen to remove NO_IRQ before moving the code, and probably > the rename from host to domain. Haha. Yeah, I debated reordering those a bit, but it would have created a bunch of rebase work for little benefit. Unless someone really complains loudly, I'm going to leave it in the order as is. > I haven't studied the patches in > detail since your tree is based on linux-next and my drive doesn't > have space for that. It took me a while to realize the code removed > from the header file in 4/14 (powerpc use commmon host) was actually > moved to irq-domain in 1/14 (a comment to that effect would be nice). Okay, I'll add a comment to that effect. If I rebase to Linus' tree after 3.3-rc1 is released, can you help me test? g. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
