diff options
author | alc <alc@FreeBSD.org> | 2003-11-01 08:57:26 +0000 |
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committer | alc <alc@FreeBSD.org> | 2003-11-01 08:57:26 +0000 |
commit | 716130a6f9a9ee9967af6ade439c5ec39ba544d0 (patch) | |
tree | 5536bd0794b7e53a43e6c3bd5db2156c18cc9f73 /sys/vm | |
parent | 5e44220cea810f5870dc11996bd1c60976d236ef (diff) | |
download | FreeBSD-src-716130a6f9a9ee9967af6ade439c5ec39ba544d0.zip FreeBSD-src-716130a6f9a9ee9967af6ade439c5ec39ba544d0.tar.gz |
- Modify swap_pager_copy() and its callers such that the source and
destination objects are locked on entry and exit. Add comments to
the callers noting that the locks can be released by swap_pager_copy().
- Remove several instances of GIANT_REQUIRED.
Diffstat (limited to 'sys/vm')
-rw-r--r-- | sys/vm/swap_pager.c | 21 | ||||
-rw-r--r-- | sys/vm/vm_object.c | 29 |
2 files changed, 18 insertions, 32 deletions
diff --git a/sys/vm/swap_pager.c b/sys/vm/swap_pager.c index 74597b3..a9a6afb 100644 --- a/sys/vm/swap_pager.c +++ b/sys/vm/swap_pager.c @@ -527,8 +527,6 @@ swap_pager_dealloc(vm_object_t object) { int s; - GIANT_REQUIRED; - /* * Remove from list right away so lookups will fail if we block for * pageout completion. @@ -788,7 +786,8 @@ swap_pager_copy(vm_object_t srcobject, vm_object_t dstobject, vm_pindex_t i; int s; - GIANT_REQUIRED; + VM_OBJECT_LOCK_ASSERT(srcobject, MA_OWNED); + VM_OBJECT_LOCK_ASSERT(dstobject, MA_OWNED); s = splvm(); /* @@ -841,9 +840,16 @@ swap_pager_copy(vm_object_t srcobject, vm_object_t dstobject, ); if (srcaddr != SWAPBLK_NONE) { - VM_OBJECT_LOCK(dstobject); + /* + * swp_pager_meta_build() can sleep. + */ + vm_object_pip_add(srcobject, 1); + VM_OBJECT_UNLOCK(srcobject); + vm_object_pip_add(dstobject, 1); swp_pager_meta_build(dstobject, i, srcaddr); - VM_OBJECT_UNLOCK(dstobject); + vm_object_pip_wakeup(dstobject); + VM_OBJECT_LOCK(srcobject); + vm_object_pip_wakeup(srcobject); } } else { /* @@ -862,9 +868,7 @@ swap_pager_copy(vm_object_t srcobject, vm_object_t dstobject, * double-remove the object from the swap queues. */ if (destroysource) { - VM_OBJECT_LOCK(srcobject); swp_pager_meta_free_all(srcobject); - VM_OBJECT_UNLOCK(srcobject); /* * Reverting the type is not necessary, the caller is going * to destroy srcobject directly, but I'm doing it here @@ -1800,7 +1804,6 @@ swp_pager_meta_build(vm_object_t object, vm_pindex_t pindex, daddr_t swapblk) struct swblock **pswap; int idx; - GIANT_REQUIRED; VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); /* * Convert default object to swap object if necessary @@ -2008,7 +2011,7 @@ swp_pager_meta_ctl(vm_object_t object, vm_pindex_t pindex, int flags) daddr_t r1; int idx; - GIANT_REQUIRED; + VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); /* * The meta data only exists of the object is OBJT_SWAP * and even then might not be allocated yet. diff --git a/sys/vm/vm_object.c b/sys/vm/vm_object.c index 0d904c3..3ce3819 100644 --- a/sys/vm/vm_object.c +++ b/sys/vm/vm_object.c @@ -1227,24 +1227,19 @@ vm_object_split(vm_map_entry_t entry) vm_page_busy(m); vm_page_unlock_queues(); } - VM_OBJECT_UNLOCK(new_object); if (orig_object->type == OBJT_SWAP) { - vm_object_pip_add(orig_object, 1); - VM_OBJECT_UNLOCK(orig_object); /* - * copy orig_object pages into new_object - * and destroy unneeded pages in - * shadow object. + * swap_pager_copy() can sleep, in which case the orig_object's + * and new_object's locks are released and reacquired. */ swap_pager_copy(orig_object, new_object, offidxstart, 0); - VM_OBJECT_LOCK(orig_object); - vm_object_pip_wakeup(orig_object); } VM_OBJECT_UNLOCK(orig_object); vm_page_lock_queues(); TAILQ_FOREACH(m, &new_object->memq, listq) vm_page_wakeup(m); vm_page_unlock_queues(); + VM_OBJECT_UNLOCK(new_object); entry->object.vm_object = new_object; entry->offset = 0LL; vm_object_deallocate(orig_object); @@ -1547,27 +1542,15 @@ vm_object_collapse(vm_object_t object) * Move the pager from backing_object to object. */ if (backing_object->type == OBJT_SWAP) { - vm_object_pip_add(backing_object, 1); - VM_OBJECT_UNLOCK(backing_object); /* - * scrap the paging_offset junk and do a - * discrete copy. This also removes major - * assumptions about how the swap-pager - * works from where it doesn't belong. The - * new swapper is able to optimize the - * destroy-source case. + * swap_pager_copy() can sleep, in which case + * the backing_object's and object's locks are + * released and reacquired. */ - vm_object_pip_add(object, 1); - VM_OBJECT_UNLOCK(object); swap_pager_copy( backing_object, object, OFF_TO_IDX(object->backing_object_offset), TRUE); - VM_OBJECT_LOCK(object); - vm_object_pip_wakeup(object); - - VM_OBJECT_LOCK(backing_object); - vm_object_pip_wakeup(backing_object); } /* * Object now shadows whatever backing_object did. |