Date: Sun, 19 Feb 2017 03:33:20 +0000 (UTC) From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r313933 - head/sys/amd64/amd64 Message-ID: <201702190333.v1J3XKQB067946@repo.freebsd.org>
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Author: kib Date: Sun Feb 19 03:33:20 2017 New Revision: 313933 URL: https://svnweb.freebsd.org/changeset/base/313933 Log: Microoptimize amd64/pmap.c pmap_protect_pde(). For the loop that dirties vm_pages in case superpage was written to, check the complete condition before the loop. Reviewed by: alc Sponsored by: The FreeBSD Foundation MFC after: 1 week Modified: head/sys/amd64/amd64/pmap.c Modified: head/sys/amd64/amd64/pmap.c ============================================================================== --- head/sys/amd64/amd64/pmap.c Sun Feb 19 03:17:11 2017 (r313932) +++ head/sys/amd64/amd64/pmap.c Sun Feb 19 03:33:20 2017 (r313933) @@ -3998,12 +3998,12 @@ pmap_protect_pde(pmap_t pmap, pd_entry_t anychanged = FALSE; retry: oldpde = newpde = *pde; - if (oldpde & PG_MANAGED) { + if ((oldpde & (PG_MANAGED | PG_M | PG_RW)) == + (PG_MANAGED | PG_M | PG_RW)) { eva = sva + NBPDR; for (va = sva, m = PHYS_TO_VM_PAGE(oldpde & PG_PS_FRAME); va < eva; va += PAGE_SIZE, m++) - if ((oldpde & (PG_M | PG_RW)) == (PG_M | PG_RW)) - vm_page_dirty(m); + vm_page_dirty(m); } if ((prot & VM_PROT_WRITE) == 0) newpde &= ~(PG_RW | PG_M);
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