From a759a0a00160001a346b65ca511c20714b7375a5 Mon Sep 17 00:00:00 2001 From: Andrew Turner Date: Wed, 20 Feb 2019 22:32:28 +0000 Subject: [PATCH] Call pmap_qenter for each page when creating the kcov buffer. This removes the need to allocate a buffer to hold the vm_page_t objects at the cost of extra IPIs on some architectures. Reviewed by: kib Sponsored by: DARPA, AFRL Differential Revision: https://reviews.freebsd.org/D19252 --- sys/kern/kern_kcov.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/sys/kern/kern_kcov.c b/sys/kern/kern_kcov.c index 121b1736ed2b..4b8d5dd326f6 100644 --- a/sys/kern/kern_kcov.c +++ b/sys/kern/kern_kcov.c @@ -357,7 +357,7 @@ static int kcov_alloc(struct kcov_info *info, size_t entries) { size_t n, pages; - vm_page_t *m; + vm_page_t m; KASSERT(info->kvaddr == 0, ("kcov_alloc: Already have a buffer")); KASSERT(info->state == KCOV_STATE_OPEN, @@ -376,16 +376,14 @@ kcov_alloc(struct kcov_info *info, size_t entries) info->bufobj = vm_pager_allocate(OBJT_PHYS, 0, info->bufsize, PROT_READ | PROT_WRITE, 0, curthread->td_ucred); - m = malloc(sizeof(*m) * pages, M_TEMP, M_WAITOK); VM_OBJECT_WLOCK(info->bufobj); for (n = 0; n < pages; n++) { - m[n] = vm_page_grab(info->bufobj, n, + m = vm_page_grab(info->bufobj, n, VM_ALLOC_NOBUSY | VM_ALLOC_ZERO | VM_ALLOC_WIRED); - m[n]->valid = VM_PAGE_BITS_ALL; + m->valid = VM_PAGE_BITS_ALL; + pmap_qenter(info->kvaddr + n * PAGE_SIZE, &m, 1); } VM_OBJECT_WUNLOCK(info->bufobj); - pmap_qenter(info->kvaddr, m, pages); - free(m, M_TEMP); info->entries = entries;