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path: root/drivers/s390/char/sclp_con.c
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Diffstat (limited to 'drivers/s390/char/sclp_con.c')
-rw-r--r--drivers/s390/char/sclp_con.c31
1 files changed, 30 insertions, 1 deletions
diff --git a/drivers/s390/char/sclp_con.c b/drivers/s390/char/sclp_con.c
index ecf45c54f8c..5880def98fc 100644
--- a/drivers/s390/char/sclp_con.c
+++ b/drivers/s390/char/sclp_con.c
@@ -130,6 +130,31 @@ sclp_console_timeout(unsigned long data)
}
/*
+ * Drop oldest console buffer if sclp_con_drop is set
+ */
+static int
+sclp_console_drop_buffer(void)
+{
+ struct list_head *list;
+ struct sclp_buffer *buffer;
+ void *page;
+
+ if (!sclp_console_drop)
+ return 0;
+ list = sclp_con_outqueue.next;
+ if (sclp_con_queue_running)
+ /* The first element is in I/O */
+ list = list->next;
+ if (list == &sclp_con_outqueue)
+ return 0;
+ list_del(list);
+ buffer = list_entry(list, struct sclp_buffer, list);
+ page = sclp_unmake_buffer(buffer);
+ list_add_tail((struct list_head *) page, &sclp_con_pages);
+ return 1;
+}
+
+/*
* Writes the given message to S390 system console
*/
static void
@@ -150,9 +175,13 @@ sclp_console_write(struct console *console, const char *message,
do {
/* make sure we have a console output buffer */
if (sclp_conbuf == NULL) {
+ if (list_empty(&sclp_con_pages))
+ sclp_console_full++;
while (list_empty(&sclp_con_pages)) {
if (sclp_con_suspended)
goto out;
+ if (sclp_console_drop_buffer())
+ break;
spin_unlock_irqrestore(&sclp_con_lock, flags);
sclp_sync_wait();
spin_lock_irqsave(&sclp_con_lock, flags);
@@ -297,7 +326,7 @@ sclp_console_init(void)
return rc;
/* Allocate pages for output buffering */
INIT_LIST_HEAD(&sclp_con_pages);
- for (i = 0; i < MAX_CONSOLE_PAGES; i++) {
+ for (i = 0; i < sclp_console_pages; i++) {
page = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
list_add_tail(page, &sclp_con_pages);
}