The branch main has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=e8dc2ba29c62f3be2bdeb1a09321d73644a84475
commit e8dc2ba29c62f3be2bdeb1a09321d73644a84475 Author: Konstantin Belousov <[email protected]> AuthorDate: 2021-11-29 16:28:19 +0000 Commit: Konstantin Belousov <[email protected]> CommitDate: 2021-12-04 22:20:58 +0000 swapoff(2): add a SWAPOFF_FORCE flag The flag requests skipping the heuristic which tries to avoid leaving system with more allocated memory than available from RAM and remanining swap. Reviewed by: markj Discussed with: alc Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D33165 --- sys/vm/swap_pager.c | 12 ++++++------ sys/vm/swap_pager.h | 2 ++ 2 files changed, 8 insertions(+), 6 deletions(-) diff --git a/sys/vm/swap_pager.c b/sys/vm/swap_pager.c index dc1df79f4fcd..99addb2c8e53 100644 --- a/sys/vm/swap_pager.c +++ b/sys/vm/swap_pager.c @@ -470,7 +470,7 @@ static void swp_pager_free_empty_swblk(vm_object_t, struct swblk *sb); static int swapongeom(struct vnode *); static int swaponvp(struct thread *, struct vnode *, u_long); static int swapoff_one(struct swdevt *sp, struct ucred *cred, - bool ignore_check); + u_int flags); /* * Swap bitmap functions @@ -2511,7 +2511,7 @@ sys_swapoff(struct thread *td, struct swapoff_args *uap) error = copyin(uap->name, &sa, sizeof(sa)); if (error != 0) return (error); - if (sa.flags != 0) + if ((sa.flags & ~(SWAPOFF_FORCE)) != 0) return (EINVAL); break; default: @@ -2539,14 +2539,14 @@ sys_swapoff(struct thread *td, struct swapoff_args *uap) error = EINVAL; goto done; } - error = swapoff_one(sp, td->td_ucred, false); + error = swapoff_one(sp, td->td_ucred, sa.flags); done: sx_xunlock(&swdev_syscall_lock); return (error); } static int -swapoff_one(struct swdevt *sp, struct ucred *cred, bool ignore_check) +swapoff_one(struct swdevt *sp, struct ucred *cred, u_int flags) { u_long nblks; #ifdef MAC @@ -2576,7 +2576,7 @@ swapoff_one(struct swdevt *sp, struct ucred *cred, bool ignore_check) * means that we can lose swap data when filesystems go away, * which is arguably worse. */ - if (!ignore_check && + if ((flags & SWAPOFF_FORCE) == 0 && vm_free_count() + swap_pager_avail < nblks + nswap_lowat) return (ENOMEM); @@ -2627,7 +2627,7 @@ swapoff_all(void) devname = devtoname(sp->sw_vp->v_rdev); else devname = "[file]"; - error = swapoff_one(sp, thread0.td_ucred, true); + error = swapoff_one(sp, thread0.td_ucred, SWAPOFF_FORCE); if (error != 0) { printf("Cannot remove swap device %s (error=%d), " "skipping.\n", devname, error); diff --git a/sys/vm/swap_pager.h b/sys/vm/swap_pager.h index 469de3e8eaf4..59322d49cbc9 100644 --- a/sys/vm/swap_pager.h +++ b/sys/vm/swap_pager.h @@ -77,6 +77,8 @@ struct swapoff_new_args { uintptr_t pad1[8]; }; +#define SWAPOFF_FORCE 0x00000001 + #ifdef _KERNEL extern int swap_pager_avail;
