Date: Wed, 2 Nov 2005 16:22:19 -0500 From: John Baldwin <jhb@freebsd.org> To: Scott Long <scottl@samsco.org> Cc: cvs-src@freebsd.org, src-committers@freebsd.org, cvs-all@freebsd.org Subject: Re: cvs commit: src/sys/amd64/amd64 io_apic.c local_apic.c src/sys/amd64/include apicvar.h intr_machdep.h src/sys/i386/i386 io_apic.c local_apic.c src/sys/i386/include apicvar.h intr_machdep.h Message-ID: <200511021622.21242.jhb@freebsd.org> In-Reply-To: <436928C2.8090304@samsco.org> References: <200511022011.jA2KBlHQ005559@repoman.freebsd.org> <436928C2.8090304@samsco.org>
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On Wednesday 02 November 2005 03:59 pm, Scott Long wrote: > John Baldwin wrote: > > jhb 2005-11-02 20:11:47 UTC > > > > FreeBSD src repository > > > > Modified files: > > sys/amd64/amd64 io_apic.c local_apic.c > > sys/amd64/include apicvar.h intr_machdep.h > > sys/i386/i386 io_apic.c local_apic.c > > sys/i386/include apicvar.h intr_machdep.h > > Log: > > Change the x86 code to allocate IDT vectors on-demand when an interrupt > > source is first enabled similar to how intr_event's now allocate > > ithreads on-demand. Previously, we would map IDT vectors 1:1 to IRQs. > > Since we only have 191 available IDT vectors for I/O interrupts, this > > limited us to only supporting IRQs 0-190 corresponding to the first 190 > > I/O APIC intpins. On many machines, however, each PCI-X bus has its own > > APIC even though it only has 1 or 2 devices, thus, we were reserving > > between 24 and 32 IRQs just for 1 or 2 devices and thus 24 or 32 IDT > > vectors. With this change, a machine with 100 IRQs but only 5 in use > > will only use up 5 IDT vectors. Also, this change provides an API > > (apic_alloc_vector() and apic_free_vector()) that will allow a future MSI > > interrupt source driver to request IDT vectors for use by MSI interrupts > > on x86 machines. > > > > Tested on: amd64, i386 > > > > Revision Changes Path > > 1.18 +84 -68 src/sys/amd64/amd64/io_apic.c > > 1.19 +100 -22 src/sys/amd64/amd64/local_apic.c > > 1.14 +3 -2 src/sys/amd64/include/apicvar.h > > 1.7 +29 -3 src/sys/amd64/include/intr_machdep.h > > 1.23 +84 -68 src/sys/i386/i386/io_apic.c > > 1.20 +101 -23 src/sys/i386/i386/local_apic.c > > 1.14 +3 -2 src/sys/i386/include/apicvar.h > > 1.9 +29 -3 src/sys/i386/include/intr_machdep.h > > Excellent, thanks a lot. The other savings here is the dozens of unused > ithread stack pages and pcbs. That was the earlier intr_event stuff. :-P -- John Baldwin <jhb@FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve" = http://www.FreeBSD.org
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