osfmk/default_pager/dp_backing_store.c

227 	paging_segment_t segment,
403 			 ("segment #%d: %d total, %d free\n",
745 		/* transfer of of the target segment.                      */
746 		/* We are guaranteed that the target segment cannot get    */
751 		/* do not have any backing store in the target segment     */
863 			 * Someone is already busy reclamining this paging segment.
864 			 * If it's the emergency segment we are looking at then check
872 			/* disable access to this segment */
877 			 * The "ps" segment is "off-line" now,
887 				/* segment from the list of free pages   */
889 				/* segment pages will appear to be free  */
898 				 * We couldn't delete the segment,
932 				/* re-enable access to this segment */
1095 	 * Set up the paging segment
1419 	 * Optimize case where there's only one segment.
1420 	 * paging_segment_max will index the one and only segment.
1432 			panic("Emergency paging segment missing\n");
1458 				dprintf(("Emergency swap segment:dp_pages_free before zeroing out: %d\n",dp_pages_free));
1599 	 * Find best paging segment.
1601 	 * Must pass cluster shift to find the most appropriate segment.
1603 	/* NOTE:  The addition of paging segment delete capability threatened
1606 	 * difficulty in assuring that the paging segment would continue to
1610 	 * the transfer function which is part of the segment delete path.
1611 	 * The transfer function which is part of paging segment delete is
1613 	 * The paging segment delete function treats mappings to a paging
1614 	 * segment on a vstruct by vstruct basis, locking the vstruct targeted
1618 	 * This and the ordering of the paging segment "going_away" bit setting
1655 		 * Don't immediately jump to the emergency segment. Give the
1670 					/* Someone de-activated the emergency paging segment*/
1676 					 * Someone has already activated the emergency paging segment
1678 					 * Between us having rec'd a NULL segment from ps_select_segment
1679 					 * and reaching here a new normal segment could have been added.
1680 					 * E.g. we get NULL segment and another thread just added the
1682 					 * before activating the emergency segment.
1690 					 * PS_CAN_USE is only reset from the emergency segment when it's
1692 					 * segment that has PS_CAN_USE but no clusters because it's recovery
1705 					dprintf(("Switching ON Emergency paging segment\n"));
1722 			/* With an activated emergency paging segment we still
1724 			 * emergency paging segment is exhausted.
1751 	 * first zero bit in the paging segment bitmap.
1789 	 * Lock the paging segment, clear the cluster's bitmap and increment the
2227 			 * Attempt to allocate a cluster from the paging segment
2250 	 * Byte offset in paging segment is byte offset to cluster plus
2347 	 * Loop through all clusters in this range, freeing paging segment
2373 		 * paging segment cluster pages.
3160 					 * a physical segment
3182 				 * segment and there's more to do, so try
3193 					 * if the physical segment we're about
3205 				 * segment
3211 				 * no I/O to generate for this segment
3340 	dp_offset_t	actual_offset;	/* Offset within paging segment */
3557 			 * make sure that each physical segment that we step
3569 				 * we don't need to check for physical segment
3582 						 * if the segment we're about
3802 	paging_segment_t segment,
3848 				    (VSM_PS(vsmap[j]) != segment))
3899 			    (VSM_PS(vsmap[j]) != segment))
3985 	 * segment the pages are being read from is assumed to have
3995 	 * If there are holes in a cluster (in a paging segment), we stop
4242 	 * Set up the paging segment
4311 	 * If the paging segment being activated is not the emergency
4312 	 * segment and we notice that the emergency segment is being
4314 	 * emergency segment will be back to its original state of
4324 				dprintf(("Failed to recover emergency paging segment\n"));
4326 				dprintf(("Recovered emergency paging segment\n"));