Date: Thu, 25 Nov 2010 22:06:08 +0000 (UTC) From: Colin Percival <cperciva@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r215844 - head/sys/i386/xen Message-ID: <201011252206.oAPM68sj018992@svn.freebsd.org>
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Author: cperciva Date: Thu Nov 25 22:06:07 2010 New Revision: 215844 URL: http://svn.freebsd.org/changeset/base/215844 Log: Revert r215819 and fix the bug properly. In pmap_qremove, paging table updates were being queued by pmap_kremove, but the queue wasn't being flushed; as a result, the updates didn't happen until *after* the call to pmap_invalidate_range, and old entries could stick around in the TLB. Adding a PT_UPDATES_FLUSH() call immediately before pmap_invalidate_range ensures that after the invalidation the TLB will be repopulated with the correct new entries. Thanks to: kib, avg, alc Modified: head/sys/i386/xen/pmap.c Modified: head/sys/i386/xen/pmap.c ============================================================================== --- head/sys/i386/xen/pmap.c Thu Nov 25 21:51:43 2010 (r215843) +++ head/sys/i386/xen/pmap.c Thu Nov 25 22:06:07 2010 (r215844) @@ -1292,19 +1292,7 @@ pmap_qenter(vm_offset_t sva, vm_page_t * mclp->args[0] = va; mclp->args[1] = (uint32_t)(pa & 0xffffffff); mclp->args[2] = (uint32_t)(pa >> 32); -#if 0 mclp->args[3] = (*pte & PG_V) ? UVMF_INVLPG|UVMF_ALL : 0; -#else - /* - * Somehow we seem to be ending up with pages which are in - * the TLB in spite of not having PG_V set, resulting in - * pages newly loaded into the bufcache not showing up - * immediately (i.e., accessing them provides the old data). - * As a workaround, always perform a TLB flush, even if the - * old page didn't have PG_V. - */ - mclp->args[3] = UVMF_INVLPG|UVMF_ALL; -#endif va += PAGE_SIZE; pte++; @@ -1348,6 +1336,7 @@ pmap_qremove(vm_offset_t sva, int count) pmap_kremove(va); va += PAGE_SIZE; } + PT_UPDATES_FLUSH(); pmap_invalidate_range(kernel_pmap, sva, va); critical_exit(); vm_page_unlock_queues();
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