Module Name: src
Committed By: jdolecek
Date: Thu Jun 25 14:04:30 UTC 2020
Modified Files:
src/sys/uvm: uvm_bio.c
Log Message:
make ubc_winshift / ubc_winsize constant, and based on whatever is bigger
of (1 << UBC_WINSHIFT, MAX_PAGE_SIZE)
given that default UBC_WINSHIFT is 13, this changes behaviour only
for mips and powerpc (BookE/OEA), which will now have twice as much
memory used for UBC windows; if this ever becomes a problem, it's
possible to reduce ubc_nwins in MD code similar to what is done on sparc
this eliminates variable-length arrays in ubc_fault(),
ubc_uiomove(), and ubc_zerorange() so that the stack usage can be
determined and checked in compile time
To generate a diff of this commit:
cvs rdiff -u -r1.117 -r1.118 src/sys/uvm/uvm_bio.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/uvm/uvm_bio.c
diff -u src/sys/uvm/uvm_bio.c:1.117 src/sys/uvm/uvm_bio.c:1.118
--- src/sys/uvm/uvm_bio.c:1.117 Mon May 25 19:29:08 2020
+++ src/sys/uvm/uvm_bio.c Thu Jun 25 14:04:30 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: uvm_bio.c,v 1.117 2020/05/25 19:29:08 ad Exp $ */
+/* $NetBSD: uvm_bio.c,v 1.118 2020/06/25 14:04:30 jdolecek Exp $ */
/*
* Copyright (c) 1998 Chuck Silvers.
@@ -34,7 +34,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uvm_bio.c,v 1.117 2020/05/25 19:29:08 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uvm_bio.c,v 1.118 2020/06/25 14:04:30 jdolecek Exp $");
#include "opt_uvmhist.h"
#include "opt_ubc.h"
@@ -45,6 +45,7 @@ __KERNEL_RCSID(0, "$NetBSD: uvm_bio.c,v
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/vnode.h>
+#include <sys/bitops.h> /* for ilog2() */
#include <uvm/uvm.h>
#include <uvm/uvm_pdpolicy.h>
@@ -120,9 +121,13 @@ const struct uvm_pagerops ubc_pager = {
/* ... rest are NULL */
};
+/* Use value at least as big as maximum page size supported by architecture */
+#define UBC_MAX_WINSHIFT \
+ ((1 << UBC_WINSHIFT) > MAX_PAGE_SIZE ? UBC_WINSHIFT : ilog2(MAX_PAGE_SIZE))
+
int ubc_nwins = UBC_NWINS;
-int ubc_winshift __read_mostly = UBC_WINSHIFT;
-int ubc_winsize __read_mostly;
+const int ubc_winshift = UBC_MAX_WINSHIFT;
+const int ubc_winsize = 1 << UBC_MAX_WINSHIFT;
#if defined(PMAP_PREFER)
int ubc_nqueues;
#define UBC_NQUEUES ubc_nqueues
@@ -161,9 +166,7 @@ ubc_init(void)
/*
* Make sure ubc_winshift is sane.
*/
- if (ubc_winshift < PAGE_SHIFT)
- ubc_winshift = PAGE_SHIFT;
- ubc_winsize = 1 << ubc_winshift;
+ KASSERT(ubc_winshift >= PAGE_SHIFT);
/*
* init ubc_object.
@@ -304,7 +307,7 @@ ubc_fault(struct uvm_faultinfo *ufi, vad
struct uvm_object *uobj;
struct ubc_map *umap;
vaddr_t va, eva, ubc_offset, slot_offset;
- struct vm_page *pgs[ubc_winsize >> PAGE_SHIFT];
+ struct vm_page *pgs[howmany(ubc_winsize, MIN_PAGE_SIZE)];
int i, error, npages;
vm_prot_t prot;
@@ -732,7 +735,7 @@ ubc_uiomove(struct uvm_object *uobj, str
int flags)
{
const bool overwrite = (flags & UBC_FAULTBUSY) != 0;
- struct vm_page *pgs[ubc_winsize >> PAGE_SHIFT];
+ struct vm_page *pgs[howmany(ubc_winsize, MIN_PAGE_SIZE)];
voff_t off;
int error, npages;
@@ -798,7 +801,7 @@ ubc_uiomove(struct uvm_object *uobj, str
void
ubc_zerorange(struct uvm_object *uobj, off_t off, size_t len, int flags)
{
- struct vm_page *pgs[ubc_winsize >> PAGE_SHIFT];
+ struct vm_page *pgs[howmany(ubc_winsize, MIN_PAGE_SIZE)];
int npages;
#ifdef UBC_USE_PMAP_DIRECT
@@ -975,7 +978,7 @@ ubc_uiomove_direct(struct uvm_object *uo
const bool overwrite = (flags & UBC_FAULTBUSY) != 0;
voff_t off;
int error, npages;
- struct vm_page *pgs[ubc_winsize >> PAGE_SHIFT];
+ struct vm_page *pgs[howmany(ubc_winsize, MIN_PAGE_SIZE)];
KASSERT(todo <= uio->uio_resid);
KASSERT(((flags & UBC_WRITE) != 0 && uio->uio_rw == UIO_WRITE) ||
@@ -1043,7 +1046,7 @@ static void __noinline
ubc_zerorange_direct(struct uvm_object *uobj, off_t off, size_t todo, int flags)
{
int error, npages;
- struct vm_page *pgs[ubc_winsize >> PAGE_SHIFT];
+ struct vm_page *pgs[howmany(ubc_winsize, MIN_PAGE_SIZE)];
flags |= UBC_WRITE;
