Date: Mon, 14 Sep 2020 12:22:20 +0000 (UTC) From: Mark Johnston <markj@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-12@freebsd.org Subject: svn commit: r365718 - stable/12/sys/vm Message-ID: <202009141222.08ECMKu3006413@repo.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: markj Date: Mon Sep 14 12:22:19 2020 New Revision: 365718 URL: https://svnweb.freebsd.org/changeset/base/365718 Log: MFC r365437: vm_object_split(): Handle orig_object type changes. Modified: stable/12/sys/vm/vm_object.c Directory Properties: stable/12/ (props changed) Modified: stable/12/sys/vm/vm_object.c ============================================================================== --- stable/12/sys/vm/vm_object.c Mon Sep 14 11:03:18 2020 (r365717) +++ stable/12/sys/vm/vm_object.c Mon Sep 14 12:22:19 2020 (r365718) @@ -1313,7 +1313,7 @@ vm_object_shadow( void vm_object_split(vm_map_entry_t entry) { - vm_page_t m, m_next; + vm_page_t m, m_busy, m_next; vm_object_t orig_object, new_object, source; vm_pindex_t idx, offidxstart; vm_size_t size; @@ -1370,8 +1370,14 @@ vm_object_split(vm_map_entry_t entry) ("orig_object->charge < 0")); orig_object->charge -= ptoa(size); } + m_busy = NULL; +#ifdef INVARIANTS + idx = 0; +#endif retry: m = vm_page_find_least(orig_object, offidxstart); + KASSERT(m == NULL || idx <= m->pindex - offidxstart, + ("%s: object %p was repopulated", __func__, orig_object)); for (; m != NULL && (idx = m->pindex - offidxstart) < size; m = m_next) { m_next = TAILQ_NEXT(m, listq); @@ -1417,8 +1423,16 @@ retry: */ vm_reserv_rename(m, new_object, orig_object, offidxstart); #endif - if (orig_object->type == OBJT_SWAP) + + /* + * orig_object's type may change while sleeping, so keep track + * of the beginning of the busied range. + */ + if (orig_object->type == OBJT_SWAP) { vm_page_xbusy(m); + if (m_busy == NULL) + m_busy = m; + } } if (orig_object->type == OBJT_SWAP) { /* @@ -1426,8 +1440,9 @@ retry: * and new_object's locks are released and reacquired. */ swap_pager_copy(orig_object, new_object, offidxstart, 0); - TAILQ_FOREACH(m, &new_object->memq, listq) - vm_page_xunbusy(m); + if (m_busy != NULL) + TAILQ_FOREACH_FROM(m_busy, &new_object->memq, listq) + vm_page_xunbusy(m_busy); } VM_OBJECT_WUNLOCK(orig_object); VM_OBJECT_WUNLOCK(new_object);
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?202009141222.08ECMKu3006413>