Date: Tue, 21 Nov 2017 03:12:16 +0000 (UTC) From: Justin Hibbits <jhibbits@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r326045 - head/sys/powerpc/booke Message-ID: <201711210312.vAL3CG1x022763@repo.freebsd.org>
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Author: jhibbits Date: Tue Nov 21 03:12:16 2017 New Revision: 326045 URL: https://svnweb.freebsd.org/changeset/base/326045 Log: Check the page table before TLB1 in pmap_kextract() The vast majority of pmap_kextract() calls are looking for a physical memory address, not a device address. By checking the page table first this saves the formerly inevitable 64 (on e500mc and derivatives) iteration loop through TLB1 in the most common cases. Benchmarking this on the P5020 (e5500 core) yields a 300% throughput improvement on dtsec(4) (115Mbit/s -> 460Mbit/s) measured with iperf. Benchmarked on the P1022 (e500v2 core, 16 TLB1 entries) yields a 50% throughput improvement on tsec(4) (~93Mbit/s -> 165Mbit/s) measured with iperf. MFC after: 1 week Relnotes: Maybe (significant performance improvement) Modified: head/sys/powerpc/booke/pmap.c Modified: head/sys/powerpc/booke/pmap.c ============================================================================== --- head/sys/powerpc/booke/pmap.c Tue Nov 21 02:09:59 2017 (r326044) +++ head/sys/powerpc/booke/pmap.c Tue Nov 21 03:12:16 2017 (r326045) @@ -2089,18 +2089,23 @@ static vm_paddr_t mmu_booke_kextract(mmu_t mmu, vm_offset_t va) { tlb_entry_t e; + vm_paddr_t p; int i; - /* Check TLB1 mappings */ - for (i = 0; i < TLB1_ENTRIES; i++) { - tlb1_read_entry(&e, i); - if (!(e.mas1 & MAS1_VALID)) - continue; - if (va >= e.virt && va < e.virt + e.size) - return (e.phys + (va - e.virt)); + p = pte_vatopa(mmu, kernel_pmap, va); + + if (p == 0) { + /* Check TLB1 mappings */ + for (i = 0; i < TLB1_ENTRIES; i++) { + tlb1_read_entry(&e, i); + if (!(e.mas1 & MAS1_VALID)) + continue; + if (va >= e.virt && va < e.virt + e.size) + return (e.phys + (va - e.virt)); + } } - return (pte_vatopa(mmu, kernel_pmap, va)); + return (p); } /*
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