Dynamic buffer cache. Initial diff from mickey@, okay art@ beck@ toby@

deraadt@ dlg@.

1 files changed, 11 insertions, 77 deletions

diff --git a/sys/arch/arm/arm/arm32_machdep.c b/sys/arch/arm/arm/arm32_machdep.c
index ce628cccc41..81b7fe52ca6 100644
--- a/sys/arch/arm/arm/arm32_machdep.c
+++ b/sys/arch/arm/arm/arm32_machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: arm32_machdep.c,v 1.23 2007/05/23 20:33:46 pvalchev Exp $	*/
+/*	$OpenBSD: arm32_machdep.c,v 1.24 2007/05/26 20:26:50 pedro Exp $	*/
 /*	$NetBSD: arm32_machdep.c,v 1.42 2003/12/30 12:33:15 pk Exp $	*/
 
 /*
@@ -76,12 +76,6 @@ struct vm_map *phys_map = NULL;
 extern int physmem;
 caddr_t allocsys(caddr_t);
 
-#ifdef  NBUF
-int     nbuf = NBUF;
-#else
-int     nbuf = 0;
-#endif
-
 #ifndef BUFCACHEPERCENT
 #define BUFCACHEPERCENT 5
 #endif
@@ -263,8 +257,6 @@ cpu_startup()
 	paddr_t maxaddr;
 	caddr_t sysbase;
 	caddr_t size;
-	vsize_t bufsize;
-	int base, residual;
 
 	proc0paddr = (struct user *)kernelstack.pv_va;
 	proc0.p_addr = proc0paddr;
@@ -328,49 +320,18 @@ cpu_startup()
 	if ((caddr_t)((allocsys(sysbase) - sysbase)) != size)
 		panic("cpu_startup: system table size inconsistency");
 
-   	/*
-	 * Now allocate buffers proper.  They are different than the above
-	 * in that they usually occupy more virtual memory than physical.
+	/*
+	 * Determine how many buffers to allocate.
+	 * We allocate bufcachepercent% of memory for buffer space.
 	 */
-	bufsize = MAXBSIZE * nbuf;
-	if (uvm_map(kernel_map, (vaddr_t *)&buffers, round_page(bufsize),
-	    NULL, UVM_UNKNOWN_OFFSET, 0,
-	    UVM_MAPFLAG(UVM_PROT_NONE, UVM_PROT_NONE, UVM_INH_NONE,
-	    UVM_ADV_NORMAL, 0)) != 0)
-		panic("cpu_startup: cannot allocate UVM space for buffers");
-	minaddr = (vaddr_t)buffers;
-	if ((bufpages / nbuf) >= btoc(MAXBSIZE)) {
-		/* don't want to alloc more physical mem than needed */
-		bufpages = btoc(MAXBSIZE) * nbuf;
-	}
+	if (bufpages == 0)
+		bufpages = physmem * bufcachepercent / 100;
 
-	base = bufpages / nbuf;
-	residual = bufpages % nbuf;
-	for (loop = 0; loop < nbuf; ++loop) {
-		vsize_t curbufsize;
-		vaddr_t curbuf;
-		struct vm_page *pg;
-
-		/*
-		 * Each buffer has MAXBSIZE bytes of VM space allocated.  Of
-		 * that MAXBSIZE space, we allocate and map (base+1) pages
-		 * for the first "residual" buffers, and then we allocate
-		 * "base" pages for the rest.
-		 */
-		curbuf = (vaddr_t) buffers + (loop * MAXBSIZE);
-		curbufsize = NBPG * ((loop < residual) ? (base+1) : base);
-
-		while (curbufsize) {
-			pg = uvm_pagealloc(NULL, 0, NULL, 0);
-			if (pg == NULL)
-				panic("cpu_startup: not enough memory for buffer cache");
-			pmap_kenter_pa(curbuf, VM_PAGE_TO_PHYS(pg),
-				VM_PROT_READ|VM_PROT_WRITE);
-			curbuf += PAGE_SIZE;
-			curbufsize -= PAGE_SIZE;
-		}
-	}
-	pmap_update(pmap_kernel());
+	/* Restrict to at most 25% filled kvm */
+	if (bufpages >
+	    (VM_MAX_KERNEL_ADDRESS-VM_MIN_KERNEL_ADDRESS) / PAGE_SIZE / 4) 
+		bufpages = (VM_MAX_KERNEL_ADDRESS-VM_MIN_KERNEL_ADDRESS) /
+		    PAGE_SIZE / 4;
 
 	/*
 	 * Allocate a submap for exec arguments.  This map effectively
@@ -557,33 +518,6 @@ allocsys(caddr_t v)
 	valloc(msghdrs, struct msg, msginfo.msgtql);
 	valloc(msqids, struct msqid_ds, msginfo.msgmni);
 #endif
-	/*
-	 * Determine how many buffers to allocate.  We use 10% of the
-	 * first 2MB of memory, and 5% of the rest, with a minimum of 16
-	 * buffers.  We allocate 1/2 as many swap buffer headers as file
-	 * i/o buffers.
-	 */
-	if (bufpages == 0) {
-		bufpages = (btoc(2 * 1024 * 1024) + physmem) *
-		    bufcachepercent / 100;
-	}
-	if (nbuf == 0) {
-		nbuf = bufpages;
-		if (nbuf < 16)
-			nbuf = 16;
-	}
-
-	/* Restrict to at most 35% filled kvm */
-	/* XXX - This needs UBC... */
-	if (nbuf >
-	    (VM_MAX_KERNEL_ADDRESS-VM_MIN_KERNEL_ADDRESS) / MAXBSIZE * 35 / 100) 
-		nbuf = (VM_MAX_KERNEL_ADDRESS-VM_MIN_KERNEL_ADDRESS) /
-		    MAXBSIZE * 35 / 100;
-
-	/* More buffer pages than fits into the buffers is senseless.  */
-	if (bufpages > nbuf * MAXBSIZE / PAGE_SIZE)
-		bufpages = nbuf * MAXBSIZE / PAGE_SIZE;
 
-	valloc(buf, struct buf, nbuf);
 	return v;
 }