Date: Wed, 30 May 2018 20:24:21 +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: r334397 - head/sys/i386/i386 Message-ID: <201805302024.w4UKOLs1073909@repo.freebsd.org>
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Author: kib Date: Wed May 30 20:24:21 2018 New Revision: 334397 URL: https://svnweb.freebsd.org/changeset/base/334397 Log: Avoid unneccessary TLB shootdowns in pmap_unwire_ptp() for user pmaps, which no longer create recursive page table mappings. Benchmarked by: bde Tested by: pho Sponsored by: The FreeBSD Foundation Modified: head/sys/i386/i386/pmap.c Modified: head/sys/i386/i386/pmap.c ============================================================================== --- head/sys/i386/i386/pmap.c Wed May 30 20:16:17 2018 (r334396) +++ head/sys/i386/i386/pmap.c Wed May 30 20:24:21 2018 (r334397) @@ -1872,7 +1872,6 @@ pmap_unwire_ptp(pmap_t pmap, vm_page_t m, struct spgli static void _pmap_unwire_ptp(pmap_t pmap, vm_page_t m, struct spglist *free) { - vm_offset_t pteva; /* * unmap the page table page @@ -1881,16 +1880,13 @@ _pmap_unwire_ptp(pmap_t pmap, vm_page_t m, struct spgl --pmap->pm_stats.resident_count; /* - * Do an invltlb to make the invalidated mapping - * take effect immediately. + * There is not need to invalidate the recursive mapping since + * we never instantiate such mapping for the usermode pmaps, + * and never remove page table pages from the kernel pmap. + * Put page on a list so that it is released since all TLB + * shootdown is done. */ - pteva = VM_MAXUSER_ADDRESS + i386_ptob(m->pindex); - pmap_invalidate_page(pmap, pteva); - - /* - * Put page on a list so that it is released after - * *ALL* TLB shootdown is done - */ + MPASS(pmap != kernel_pmap); pmap_add_delayed_free_list(m, free, TRUE); }
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