Date: Sat, 12 Jul 2025 01:44:20 GMT From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: 7b2ec2a56215 - stable/14 - amd64 pmap: update comment in pmap_demote_DMAP() explaining the len<NBPDP check Message-ID: <202507120144.56C1iKqG050535@gitrepo.freebsd.org>
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The branch stable/14 has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=7b2ec2a562154c84f79140f1b174f649bfa0752f commit 7b2ec2a562154c84f79140f1b174f649bfa0752f Author: Konstantin Belousov <kib@FreeBSD.org> AuthorDate: 2025-06-22 16:49:45 +0000 Commit: Konstantin Belousov <kib@FreeBSD.org> CommitDate: 2025-07-12 01:41:33 +0000 amd64 pmap: update comment in pmap_demote_DMAP() explaining the len<NBPDP check (cherry picked from commit ee502c8531833d7a0d4bc4c72cc05227f4a3715a) --- sys/amd64/amd64/pmap.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c index 6259ad33c6a1..77a836df46ad 100644 --- a/sys/amd64/amd64/pmap.c +++ b/sys/amd64/amd64/pmap.c @@ -9927,11 +9927,13 @@ pmap_change_props_locked(vm_offset_t va, vm_size_t size, vm_prot_t prot, } /* - * Demotes any mapping within the direct map region that covers more than the - * specified range of physical addresses. This range's size must be a power - * of two and its starting address must be a multiple of its size. Since the - * demotion does not change any attributes of the mapping, a TLB invalidation - * is not mandatory. The caller may, however, request a TLB invalidation. + * Demotes any mapping within the direct map region that covers more + * than the specified range of physical addresses. This range's size + * must be a power of two and its starting address must be a multiple + * of its size, which means that any pdp from the mapping is fully + * covered by the range if len > NBPDP. Since the demotion does not + * change any attributes of the mapping, a TLB invalidation is not + * mandatory. The caller may, however, request a TLB invalidation. */ void pmap_demote_DMAP(vm_paddr_t base, vm_size_t len, boolean_t invalidate)
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