On (10/01/18 14:52), Sergey Senozhatsky wrote:
> On (09/29/18 20:13), Sergey Senozhatsky wrote:
> > We used to flush "incomplete" cont lines (fragments) from console_unlock().
> >
> > void console_unlock(void)
> > {
> > ...
> > /* flush buffered message fragment immediately to console */
> > console_cont_flush(text, sizeof(text));
> > again:
> > for (;;) {
> > ...
> > }
> > ...
> > }
> >
> > Unless I'm missing something, we don't anymore.
> > Since 5c2992ee7fd8a29d04125dc0aa3522784c5fa5eb.
> > Now we print only log_buf entries. So we either wait for a \n to flush
> > a complete cont buffer, or for a race to preliminary flush cont buffer.
>
> BTW, it just crossed my mind:
One more thing.
Since we don't print cont fragments to the consoles anymore, do we still
need the "extended consoles disable kernel cont support" thing?
cont lines are proper log_buf entries now, there is nothing to reassemble
according to "consecutive continuation flags". Or am I wrong?
---
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 308497194bd4..e72cb793aff1 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -192,16 +192,7 @@ int devkmsg_sysctl_set_loglvl(struct ctl_table *table, int
write,
return 0;
}
-/*
- * Number of registered extended console drivers.
- *
- * If extended consoles are present, in-kernel cont reassembly is disabled
- * and each fragment is stored as a separate log entry with proper
- * continuation flag so that every emitted message has full metadata. This
- * doesn't change the result for regular consoles or /proc/kmsg. For
- * /dev/kmsg, as long as the reader concatenates messages according to
- * consecutive continuation flags, the end result should be the same too.
- */
+/* Number of registered extended console drivers. */
static int nr_ext_console_drivers;
/*
@@ -1806,12 +1797,8 @@ static void cont_flush(void)
static bool cont_add(int facility, int level, enum log_flags flags, const char
*text, size_t len)
{
- /*
- * If ext consoles are present, flush and skip in-kernel
- * continuation. See nr_ext_console_drivers definition. Also, if
- * the line gets too long, split it up in separate records.
- */
- if (nr_ext_console_drivers || cont.len + len > sizeof(cont.buf)) {
+ /* If the line gets too long, split it up in separate records. */
+ if (cont.len + len > sizeof(cont.buf)) {
cont_flush();
return false;
}
@@ -2731,8 +2718,7 @@ void register_console(struct console *newcon)
}
if (newcon->flags & CON_EXTENDED)
- if (!nr_ext_console_drivers++)
- pr_info("printk: continuation disabled due to ext
consoles, expect more fragments in /dev/kmsg\n");
+ nr_ext_console_drivers++;
if (newcon->flags & CON_PRINTBUFFER) {
/*
---
-ss
