svn commit: r277356 - head/sys/powerpc/aim

[Nathan Whitehorn]

Author: nwhitehorn
Date: Mon Jan 19 05:14:07 2015
New Revision: 277356
URL: https://svnweb.freebsd.org/changeset/base/277356

Log:
  Provide a tunable (machdep.moea64_bpvo_pool_size) to set the bootstrap
  PVO pool size. The default errs on the exceedingly large side, so absent
  any intelligent automatic tuning, at least let the user set it to save
  RAM on memory-constrained systems.
  
  MFC after:	2 weeks

Modified:
  head/sys/powerpc/aim/mmu_oea64.c

Modified: head/sys/powerpc/aim/mmu_oea64.c
==============================================================================
--- head/sys/powerpc/aim/mmu_oea64.c	Mon Jan 19 04:56:17 2015	(r277355)
+++ head/sys/powerpc/aim/mmu_oea64.c	Mon Jan 19 05:14:07 2015	(r277356)
@@ -221,9 +221,10 @@ struct	pvo_head *moea64_pvo_table;		/* p
 uma_zone_t	moea64_upvo_zone; /* zone for pvo entries for unmanaged pages */
 uma_zone_t	moea64_mpvo_zone; /* zone for pvo entries for managed pages */
 
-#define	BPVO_POOL_SIZE	327680
 static struct	pvo_entry *moea64_bpvo_pool;
 static int	moea64_bpvo_pool_index = 0;
+static int	moea64_bpvo_pool_size = 327680;
+TUNABLE_INT("machdep.moea64_bpvo_pool_size", &moea64_bpvo_pool_size);
 SYSCTL_INT(_machdep, OID_AUTO, moea64_allocated_bpvo_entries, CTLFLAG_RD, 
     &moea64_bpvo_pool_index, 0, "");
 
@@ -647,7 +648,7 @@ moea64_setup_direct_map(mmu_t mmup, vm_o
 		off = (vm_offset_t)(moea64_pvo_table);
 		for (pa = off; pa < off + size; pa += PAGE_SIZE) 
 			moea64_kenter(mmup, pa, pa);
-		size = BPVO_POOL_SIZE*sizeof(struct pvo_entry);
+		size = moea64_bpvo_pool_size*sizeof(struct pvo_entry);
 		off = (vm_offset_t)(moea64_bpvo_pool);
 		for (pa = off; pa < off + size; pa += PAGE_SIZE) 
 		moea64_kenter(mmup, pa, pa);
@@ -815,7 +816,7 @@ moea64_mid_bootstrap(mmu_t mmup, vm_offs
 	 * Initialise the unmanaged pvo pool.
 	 */
 	moea64_bpvo_pool = (struct pvo_entry *)moea64_bootstrap_alloc(
-		BPVO_POOL_SIZE*sizeof(struct pvo_entry), 0);
+		moea64_bpvo_pool_size*sizeof(struct pvo_entry), 0);
 	moea64_bpvo_pool_index = 0;
 
 	/*
@@ -2282,10 +2283,10 @@ moea64_pvo_enter(mmu_t mmu, pmap_t pm, u
 	 * If we aren't overwriting a mapping, try to allocate.
 	 */
 	if (bootstrap) {
-		if (moea64_bpvo_pool_index >= BPVO_POOL_SIZE) {
+		if (moea64_bpvo_pool_index >= moea64_bpvo_pool_size) {
 			panic("moea64_enter: bpvo pool exhausted, %d, %d, %zd",
-			      moea64_bpvo_pool_index, BPVO_POOL_SIZE, 
-			      BPVO_POOL_SIZE * sizeof(struct pvo_entry));
+			      moea64_bpvo_pool_index, moea64_bpvo_pool_size, 
+			      moea64_bpvo_pool_size * sizeof(struct pvo_entry));
 		}
 		pvo = &moea64_bpvo_pool[moea64_bpvo_pool_index];
 		moea64_bpvo_pool_index++;