Author: markj Date: Mon Aug 17 17:14:56 2020 New Revision: 364317 URL: https://svnweb.freebsd.org/changeset/base/364317
Log: Skip Linux madvise(MADV_DONTNEED) on unmanaged objects. vm_object_madvise() is a no-op for unmanaged objects, but we should also limit the scope of mappings on which pmap_remove() is called. In particular, with the WIP largepage shm objects patch the kernel must remove mappings of such objects along superpage boundaries, and without this check Linux madvise(MADV_DONTNEED) could violate that requirement. Reviewed by: alc, kib MFC with: r362631 Sponsored by: Juniper Networks, Klara Inc. Differential Revision: https://reviews.freebsd.org/D26084 Modified: head/sys/compat/linux/linux_mmap.c Modified: head/sys/compat/linux/linux_mmap.c ============================================================================== --- head/sys/compat/linux/linux_mmap.c Mon Aug 17 17:07:05 2020 (r364316) +++ head/sys/compat/linux/linux_mmap.c Mon Aug 17 17:14:56 2020 (r364317) @@ -282,6 +282,8 @@ linux_madvise_dontneed(struct thread *td, vm_offset_t object = entry->object.vm_object; if (object == NULL) continue; + if ((object->flags & (OBJ_UNMANAGED | OBJ_FICTITIOUS)) != 0) + continue; pstart = OFF_TO_IDX(entry->offset); if (start > entry->start) { _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
