Date: Wed, 02 Nov 2005 13:59:46 -0700 From: Scott Long <scottl@samsco.org> To: John Baldwin <jhb@FreeBSD.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: <436928C2.8090304@samsco.org> In-Reply-To: <200511022011.jA2KBlHQ005559@repoman.freebsd.org> References: <200511022011.jA2KBlHQ005559@repoman.freebsd.org>
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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. Scott
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