From e9d37c9f8d5dd0072a00e3c7db33b0cc36c93ca4 Mon Sep 17 00:00:00 2001 From: Konstantin Belousov Date: Sun, 1 May 2016 17:48:43 +0000 Subject: [PATCH] Avoid duplicated calls to pmap_page_get_memattr(). Avoid logging inconsistency for the /dev/mem device at all. The driver leaves memattr intact, and the corrective action in the device pager handles it right. In the logged warning, name the driver we blame, and show memory attributes values. Reported and tested by: pho Reviewed by: alc Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D6149 --- sys/vm/device_pager.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/sys/vm/device_pager.c b/sys/vm/device_pager.c index a4f0d6e97a0..2080fdf963a 100644 --- a/sys/vm/device_pager.c +++ b/sys/vm/device_pager.c @@ -299,7 +299,7 @@ old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset, int prot, struct cdevsw *csw; struct file *fpop; struct thread *td; - vm_memattr_t memattr; + vm_memattr_t memattr, memattr1; int ref, ret; memattr = object->memattr; @@ -327,10 +327,18 @@ old_dev_pager_fault(vm_object_t object, vm_ooffset_t offset, int prot, /* If "paddr" is a real page, perform a sanity check on "memattr". */ if ((m_paddr = vm_phys_paddr_to_vm_page(paddr)) != NULL && - pmap_page_get_memattr(m_paddr) != memattr) { - memattr = pmap_page_get_memattr(m_paddr); - printf( - "WARNING: A device driver has set \"memattr\" inconsistently.\n"); + (memattr1 = pmap_page_get_memattr(m_paddr)) != memattr) { + /* + * For the /dev/mem d_mmap routine to return the + * correct memattr, pmap_page_get_memattr() needs to + * be called, which we do there. + */ + if ((csw->d_flags & D_MEM) == 0) { + printf("WARNING: Device driver %s has set " + "\"memattr\" inconsistently (drv %u pmap %u).\n", + csw->d_name, memattr, memattr1); + } + memattr = memattr1; } if (((*mres)->flags & PG_FICTITIOUS) != 0) { /*