From abdab7b633c7b8b3a221659713c068bca81157dd Mon Sep 17 00:00:00 2001 From: Doug Moore Date: Sun, 17 Nov 2019 18:38:37 +0000 Subject: [PATCH] Add a helper function for testing a swap block and freeing it if empty. Submitted by: ota_j.email.ne.jp Approved by: alc, kib, dougm Differential Revision: https://reviews.freebsd.org/D22402 --- sys/vm/swap_pager.c | 29 +++++++++++++++++++---------- 1 file changed, 19 insertions(+), 10 deletions(-) diff --git a/sys/vm/swap_pager.c b/sys/vm/swap_pager.c index fd614b20d9ee..430d95759088 100644 --- a/sys/vm/swap_pager.c +++ b/sys/vm/swap_pager.c @@ -407,6 +407,7 @@ SYSCTL_INT(_vm, OID_AUTO, dmmax, CTLFLAG_RD, &nsw_cluster_max, 0, static void swp_sizecheck(void); static void swp_pager_async_iodone(struct buf *bp); static bool swp_pager_swblk_empty(struct swblk *sb, int start, int limit); +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); @@ -1872,6 +1873,21 @@ swp_pager_swblk_empty(struct swblk *sb, int start, int limit) } return (true); } + +/* + * SWP_PAGER_FREE_EMPTY_SWBLK() - frees if a block is free + * + * Nothing is done if the block is still in use. + */ +static void +swp_pager_free_empty_swblk(vm_object_t object, struct swblk *sb) +{ + + if (swp_pager_swblk_empty(sb, 0, SWAP_META_PAGES)) { + SWAP_PCTRIE_REMOVE(&object->un_pager.swp.swp_blks, sb->p); + uma_zfree(swblk_zone, sb); + } +} /* * SWP_PAGER_META_BUILD() - add swap block to swap meta data for object @@ -1990,11 +2006,8 @@ allocated: /* * Free the swblk if we end up with the empty page run. */ - if (swapblk == SWAPBLK_NONE && - swp_pager_swblk_empty(sb, 0, SWAP_META_PAGES)) { - SWAP_PCTRIE_REMOVE(&object->un_pager.swp.swp_blks, rdpi); - uma_zfree(swblk_zone, sb); - } + if (swapblk == SWAPBLK_NONE) + swp_pager_free_empty_swblk(object, sb); return (prev_swapblk); } @@ -2140,11 +2153,7 @@ swp_pager_meta_ctl(vm_object_t object, vm_pindex_t pindex, int flags) return (SWAPBLK_NONE); if ((flags & SWM_POP) != 0) { sb->d[pindex % SWAP_META_PAGES] = SWAPBLK_NONE; - if (swp_pager_swblk_empty(sb, 0, SWAP_META_PAGES)) { - SWAP_PCTRIE_REMOVE(&object->un_pager.swp.swp_blks, - rounddown(pindex, SWAP_META_PAGES)); - uma_zfree(swblk_zone, sb); - } + swp_pager_free_empty_swblk(object, sb); } return (r1); }