[PATCH] Print out /proc/interrupts to kmsg ~30s after boot

[Sultan Alsawaf]

---
 fs/proc/Makefile           |  1 +
 fs/proc/interrupts_print.c | 42 ++++++++++++++++++++++++++++++++++++++++++
 kernel/printk/printk.c     |  2 +-
 3 files changed, 44 insertions(+), 1 deletion(-)
 create mode 100644 fs/proc/interrupts_print.c

diff --git a/fs/proc/Makefile b/fs/proc/Makefile
index ead487e80510..9bd462cec4ec 100644
--- a/fs/proc/Makefile
+++ b/fs/proc/Makefile
@@ -33,3 +33,4 @@ proc-$(CONFIG_PROC_KCORE)	+= kcore.o
 proc-$(CONFIG_PROC_VMCORE)	+= vmcore.o
 proc-$(CONFIG_PRINTK)	+= kmsg.o
 proc-$(CONFIG_PROC_PAGE_MONITOR)	+= page.o
+obj-y += interrupts_print.o
diff --git a/fs/proc/interrupts_print.c b/fs/proc/interrupts_print.c
new file mode 100644
index 000000000000..4981dca3b828
--- /dev/null
+++ b/fs/proc/interrupts_print.c
@@ -0,0 +1,42 @@
+#include <linux/slab.h>
+#include <linux/syscalls.h>
+#include <linux/workqueue.h>
+
+#define BUF_MAX_LEN (10000)
+
+static struct delayed_work intr_print_dwork;
+
+static void print_out_interrupts(struct work_struct *work)
+{
+	char *buf;
+	int fd, i;
+
+	buf = kzalloc(BUF_MAX_LEN, GFP_KERNEL);
+	if (!buf)
+		return;
+
+	fd = sys_open("/proc/interrupts", O_RDONLY, 0444);
+	if (fd < 0)
+		goto free_buf;
+
+	for (i = 0; i < BUF_MAX_LEN - 1; i++) {
+		if (sys_read(fd, buf + i, 1) != 1)
+			break;
+	}
+	sys_close(fd);
+
+	printk("/proc/interrupts dump: \n|%s|\n", buf);
+
+free_buf:
+	kfree(buf);
+}
+
+static int __init intr_print_init(void)
+{
+	INIT_DELAYED_WORK(&intr_print_dwork, print_out_interrupts);
+	schedule_delayed_work(&intr_print_dwork,
+		msecs_to_jiffies(30 * MSEC_PER_SEC));
+
+	return 0;
+}
+device_initcall(intr_print_init);
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index f274fbef821d..2d3151ce5f24 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -428,7 +428,7 @@ static u64 clear_seq;
 static u32 clear_idx;
 
 #define PREFIX_MAX		32
-#define LOG_LINE_MAX		(1024 - PREFIX_MAX)
+#define LOG_LINE_MAX		(10000)
 
 #define LOG_LEVEL(v)		((v) & 0x07)
 #define LOG_FACILITY(v)		((v) >> 3 & 0xff)
-- 
2.14.1