Mailing List Archive

ChangeSet 1.1159.256.94, 2005/04/15 00:30:47+01:00, kaf24@firebug.cl.cam.ac.uk

Add a xencons_bufsz= option to allow a larger than usual console
buffer to be allocated. Reduces chance of console output being
truncated.
Signed-off-by: Keir Fraser <keir@xensource.com>



console.c | 37 +++++++++++++++++++++++++------------
1 files changed, 25 insertions(+), 12 deletions(-)


diff -Nru a/linux-2.6.11-xen-sparse/drivers/xen/console/console.c b/linux-2.6.11-xen-sparse/drivers/xen/console/console.c
--- a/linux-2.6.11-xen-sparse/drivers/xen/console/console.c 2005-04-14 20:02:47 -04:00
+++ b/linux-2.6.11-xen-sparse/drivers/xen/console/console.c 2005-04-14 20:02:47 -04:00
@@ -44,6 +44,7 @@
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/console.h>
+#include <linux/bootmem.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
@@ -77,11 +78,21 @@
__setup("xencons=", xencons_setup);

/* The kernel and user-land drivers share a common transmit buffer. */
-#define WBUF_SIZE 4096
-#define WBUF_MASK(_i) ((_i)&(WBUF_SIZE-1))
-static char wbuf[WBUF_SIZE];
+static unsigned int wbuf_size = 4096;
+#define WBUF_MASK(_i) ((_i)&(wbuf_size-1))
+static char *wbuf;
static unsigned int wc, wp; /* write_cons, write_prod */

+static int __init xencons_bufsz_setup(char *str)
+{
+ unsigned int goal;
+ goal = simple_strtoul(str, NULL, 0);
+ while ( wbuf_size < goal )
+ wbuf_size <<= 1;
+ return 1;
+}
+__setup("xencons_bufsz=", xencons_bufsz_setup);
+
/* This lock protects accesses to the common transmit buffer. */
static spinlock_t xencons_lock = SPIN_LOCK_UNLOCKED;

@@ -114,7 +125,7 @@

for ( i = 0; i < count; i++ )
{
- if ( (wp - wc) >= (WBUF_SIZE - 1) )
+ if ( (wp - wc) >= (wbuf_size - 1) )
break;
if ( (wbuf[WBUF_MASK(wp++)] = s[i]) == '\n' )
wbuf[WBUF_MASK(wp++)] = '\r';
@@ -195,6 +206,8 @@
else
strcpy(kcons_info.name, "tty");

+ wbuf = alloc_bootmem(wbuf_size);
+
register_console(&kcons_info);
return __RETCODE;
}
@@ -246,8 +259,8 @@
continue;
if ( sz > sizeof(msg.msg) )
sz = sizeof(msg.msg);
- if ( sz > (WBUF_SIZE - WBUF_MASK(wc)) )
- sz = WBUF_SIZE - WBUF_MASK(wc);
+ if ( sz > (wbuf_size - WBUF_MASK(wc)) )
+ sz = wbuf_size - WBUF_MASK(wc);

msg.type = CMSG_CONSOLE;
msg.subtype = CMSG_CONSOLE_DATA;
@@ -315,8 +328,8 @@
while ( wc != wp )
{
sz = wp - wc;
- if ( sz > (WBUF_SIZE - WBUF_MASK(wc)) )
- sz = WBUF_SIZE - WBUF_MASK(wc);
+ if ( sz > (wbuf_size - WBUF_MASK(wc)) )
+ sz = wbuf_size - WBUF_MASK(wc);
kcons_write_dom0(NULL, &wbuf[WBUF_MASK(wc)], sz);
wc += sz;
work_done = 1;
@@ -344,8 +357,8 @@
sz = wp - wc;
if ( sz > sizeof(msg.msg) )
sz = sizeof(msg.msg);
- if ( sz > (WBUF_SIZE - WBUF_MASK(wc)) )
- sz = WBUF_SIZE - WBUF_MASK(wc);
+ if ( sz > (wbuf_size - WBUF_MASK(wc)) )
+ sz = wbuf_size - WBUF_MASK(wc);

msg.type = CMSG_CONSOLE;
msg.subtype = CMSG_CONSOLE_DATA;
@@ -409,7 +422,7 @@

static int xencons_write_room(struct tty_struct *tty)
{
- return WBUF_SIZE - (wp - wc);
+ return wbuf_size - (wp - wc);
}

static int xencons_chars_in_buffer(struct tty_struct *tty)
@@ -468,7 +481,7 @@
static inline int __xencons_put_char(int ch)
{
char _ch = (char)ch;
- if ( (wp - wc) == WBUF_SIZE )
+ if ( (wp - wc) == wbuf_size )
return 0;
wbuf[WBUF_MASK(wp++)] = _ch;
return 1;

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