Date: Tue, 15 Nov 2022 12:38:06 GMT From: Andrew Turner <andrew@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 0b976be033c2 - main - Disable superpage use for stage 2 arm64 mappings Message-ID: <202211151238.2AFCc6Ds087545@gitrepo.freebsd.org>
next in thread | raw e-mail | index | archive | help
The branch main has been updated by andrew: URL: https://cgit.FreeBSD.org/src/commit/?id=0b976be033c2d7ad774da341e66aa69bfdb7f0ce commit 0b976be033c2d7ad774da341e66aa69bfdb7f0ce Author: Andrew Turner <andrew@FreeBSD.org> AuthorDate: 2022-11-07 11:21:42 +0000 Commit: Andrew Turner <andrew@FreeBSD.org> CommitDate: 2022-11-15 12:33:39 +0000 Disable superpage use for stage 2 arm64 mappings When modifying a stage 2 mapping we may need to call into the hypervisor to invalidate the TLB. Until it is known if the cost of this operation is less than the performance gains superpages offers disable their use. Reviewed by: kib. markj Sponsored by: Innovate UK Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D37299 --- sys/arm64/arm64/pmap.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/sys/arm64/arm64/pmap.c b/sys/arm64/arm64/pmap.c index 8a73fb1c5180..1fefcb491e06 100644 --- a/sys/arm64/arm64/pmap.c +++ b/sys/arm64/arm64/pmap.c @@ -685,8 +685,15 @@ pmap_pte_exists(pmap_t pmap, vm_offset_t va, int level, const char *diag) } bool -pmap_ps_enabled(pmap_t pmap __unused) +pmap_ps_enabled(pmap_t pmap) { + /* + * Promotion requires a hypervisor call when the kernel is running + * in EL1. To stop this disable superpage support on non-stage 1 + * pmaps for now. + */ + if (pmap->pm_stage != PM_STAGE1) + return (false); return (superpages_enabled != 0); }
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?202211151238.2AFCc6Ds087545>