Date: Sun, 1 Sep 2019 00:33:16 +0000 (UTC) From: Kyle Evans <kevans@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r351650 - head/sys/kern Message-ID: <201909010033.x810XGa9036904@repo.freebsd.org>
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Author: kevans Date: Sun Sep 1 00:33:16 2019 New Revision: 351650 URL: https://svnweb.freebsd.org/changeset/base/351650 Log: posixshm: switch to OBJT_SWAP in advance of other changes Future changes to posixshm will start tracking writeable mappings in order to support file sealing. Tracking writeable mappings for an OBJT_DEFAULT object is complicated as it may be swapped out and converted to an OBJT_SWAP. One may generically add this tracking for vm_object, but this is difficult to do without increasing memory footprint of vm_object and blowing up memory usage by a significant amount. On the other hand, the swap pager can be expanded to track writeable mappings without increasing vm_object size. This change is currently in D21456. Switch over to OBJT_SWAP in advance of the other changes to the swap pager and posixshm. Modified: head/sys/kern/uipc_shm.c Modified: head/sys/kern/uipc_shm.c ============================================================================== --- head/sys/kern/uipc_shm.c Sat Aug 31 21:28:06 2019 (r351649) +++ head/sys/kern/uipc_shm.c Sun Sep 1 00:33:16 2019 (r351650) @@ -549,7 +549,7 @@ shm_alloc(struct ucred *ucred, mode_t mode) shmfd->shm_uid = ucred->cr_uid; shmfd->shm_gid = ucred->cr_gid; shmfd->shm_mode = mode; - shmfd->shm_object = vm_pager_allocate(OBJT_DEFAULT, NULL, + shmfd->shm_object = vm_pager_allocate(OBJT_SWAP, NULL, shmfd->shm_size, VM_PROT_DEFAULT, 0, ucred); KASSERT(shmfd->shm_object != NULL, ("shm_create: vm_pager_allocate")); shmfd->shm_object->pg_color = 0;
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