Date: Tue, 31 Aug 2021 19:09:51 GMT From: Mark Johnston <markj@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: b9868ea45aa2 - stable/13 - arm64: Simplify fcmpset failure in pmap_promote_l2() Message-ID: <202108311909.17VJ9pgC074325@gitrepo.freebsd.org>
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The branch stable/13 has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=b9868ea45aa2506e354764309dad119164e2b796 commit b9868ea45aa2506e354764309dad119164e2b796 Author: Alan Cox <alc@FreeBSD.org> AuthorDate: 2021-07-07 18:16:03 +0000 Commit: Mark Johnston <markj@FreeBSD.org> CommitDate: 2021-08-31 19:09:24 +0000 arm64: Simplify fcmpset failure in pmap_promote_l2() When the initial fcmpset in pmap_promote_l2() fails, there is no need to repeat the check for the physical address being 2MB aligned or for the accessed bit being set. While the pmap is locked the hardware can only transition the accessed bit from 0 to 1, and we have already determined that it is 1 when the fcmpset fails. (cherry picked from commit 0add3c9945c85c7f766f9225866e99e2a805819b) --- sys/arm64/arm64/pmap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/sys/arm64/arm64/pmap.c b/sys/arm64/arm64/pmap.c index 35cbfc4c308c..fe26f1fea1c3 100644 --- a/sys/arm64/arm64/pmap.c +++ b/sys/arm64/arm64/pmap.c @@ -3523,7 +3523,6 @@ pmap_promote_l2(pmap_t pmap, pd_entry_t *l2, vm_offset_t va, firstl3 = pmap_l2_to_l3(l2, sva); newl2 = pmap_load(firstl3); -setl2: if (((newl2 & (~ATTR_MASK | ATTR_AF)) & L2_OFFSET) != ATTR_AF) { atomic_add_long(&pmap_l2_p_failures, 1); CTR2(KTR_PMAP, "pmap_promote_l2: failure for va %#lx" @@ -3531,6 +3530,7 @@ setl2: return; } +setl2: if ((newl2 & (ATTR_S1_AP_RW_BIT | ATTR_SW_DBM)) == (ATTR_S1_AP(ATTR_S1_AP_RO) | ATTR_SW_DBM)) { /*
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