From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To: Steven Rostedt <rostedt@goodmis.org>,
Petr Mladek <pmladek@suse.com>,
Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Alexander Potapenko <glider@google.com>,
Dmitriy Vyukov <dvyukov@google.com>,
kbuild test robot <fengguang.wu@intel.com>,
syzkaller <syzkaller@googlegroups.com>,
LKML <linux-kernel@vger.kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Subject: Re: [PATCH] printk: inject caller information into the body of message
Date: Mon, 1 Oct 2018 17:37:21 +0900 [thread overview]
Message-ID: <20181001083721.GA543@jagdpanzerIV> (raw)
In-Reply-To: <20181001055236.GA386@jagdpanzerIV>
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
next prev parent reply other threads:[~2018-10-01 8:37 UTC|newest]
Thread overview: 94+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <201804232233.CIC65675.OJSOMFQOFFHVtL@I-love.SAKURA.ne.jp>
[not found] ` <CACT4Y+boyw_Qy=y-iTnsKZrtTgF0Hk3nHN_xtqUdX4etgiYDQw@mail.gmail.com>
2018-04-24 1:33 ` printk feature for syzbot? Sergey Senozhatsky
2018-04-24 14:40 ` Steven Rostedt
2018-04-26 10:06 ` Petr Mladek
2018-05-10 4:22 ` Sergey Senozhatsky
2018-05-10 11:30 ` Petr Mladek
2018-05-10 12:11 ` Sergey Senozhatsky
2018-05-10 14:22 ` Steven Rostedt
2018-05-10 14:50 ` Tetsuo Handa
2018-05-11 1:45 ` Sergey Senozhatsky
[not found] ` <201805110238.w4B2cIGH079602@www262.sakura.ne.jp>
2018-05-11 6:21 ` Sergey Senozhatsky
2018-05-11 9:17 ` Dmitry Vyukov
2018-05-11 9:50 ` Sergey Senozhatsky
2018-05-11 11:58 ` [PATCH] printk: inject caller information into the body of message Tetsuo Handa
2018-05-17 11:21 ` Sergey Senozhatsky
2018-05-17 11:52 ` Sergey Senozhatsky
2018-05-18 12:15 ` Petr Mladek
2018-05-18 12:25 ` Dmitry Vyukov
2018-05-18 12:54 ` Petr Mladek
2018-05-18 13:08 ` Dmitry Vyukov
2018-05-24 2:21 ` Sergey Senozhatsky
2018-05-23 10:19 ` Tetsuo Handa
2018-05-24 2:14 ` Sergey Senozhatsky
2018-05-26 6:36 ` Dmitry Vyukov
2018-06-20 5:44 ` Dmitry Vyukov
2018-06-20 8:31 ` Sergey Senozhatsky
2018-06-20 8:45 ` Dmitry Vyukov
2018-06-20 9:06 ` Sergey Senozhatsky
2018-06-20 9:18 ` Sergey Senozhatsky
2018-06-20 9:31 ` Dmitry Vyukov
2018-06-20 11:07 ` Sergey Senozhatsky
2018-06-20 11:32 ` Dmitry Vyukov
2018-06-20 13:06 ` Sergey Senozhatsky
2018-06-22 13:06 ` Tetsuo Handa
2018-06-25 1:41 ` Sergey Senozhatsky
2018-06-25 9:36 ` Dmitry Vyukov
2018-06-27 10:29 ` Tetsuo Handa
2018-09-10 11:20 ` Alexander Potapenko
2018-09-12 6:53 ` Sergey Senozhatsky
2018-09-12 16:05 ` Steven Rostedt
2018-09-13 7:12 ` Sergey Senozhatsky
2018-09-13 12:26 ` Petr Mladek
2018-09-13 14:28 ` Sergey Senozhatsky
2018-09-14 1:22 ` Steven Rostedt
2018-09-14 2:15 ` Sergey Senozhatsky
2018-09-14 6:57 ` Sergey Senozhatsky
2018-09-14 10:37 ` Tetsuo Handa
2018-09-14 11:50 ` Sergey Senozhatsky
2018-09-14 12:03 ` Tetsuo Handa
2018-09-14 12:22 ` Sergey Senozhatsky
2018-09-19 11:02 ` Tetsuo Handa
2018-09-24 8:11 ` Tetsuo Handa
2018-09-27 16:10 ` Tetsuo Handa
2018-09-28 9:02 ` Sergey Senozhatsky
2018-09-28 9:09 ` Sergey Senozhatsky
2018-09-28 11:01 ` Tetsuo Handa
2018-09-29 10:51 ` Sergey Senozhatsky
2018-09-29 11:15 ` Tetsuo Handa
2018-10-01 2:37 ` Sergey Senozhatsky
2018-10-01 2:58 ` Sergey Senozhatsky
2018-10-01 11:21 ` Tetsuo Handa
2018-10-02 6:38 ` Sergey Senozhatsky
2018-10-08 10:31 ` Tetsuo Handa
2018-10-08 16:03 ` Petr Mladek
2018-10-08 20:48 ` Tetsuo Handa
2018-10-09 14:52 ` Petr Mladek
2018-10-09 21:19 ` Tetsuo Handa
2018-10-10 10:14 ` Tetsuo Handa
2018-10-11 10:20 ` Tetsuo Handa
2018-10-11 13:47 ` Steven Rostedt
2018-10-08 15:43 ` Petr Mladek
2018-09-28 8:56 ` Sergey Senozhatsky
2018-09-28 11:21 ` Tetsuo Handa
2018-09-29 11:13 ` Sergey Senozhatsky
2018-09-29 11:39 ` Tetsuo Handa
2018-10-01 5:52 ` Sergey Senozhatsky
2018-10-01 8:37 ` Sergey Senozhatsky [this message]
2018-10-01 18:06 ` Steven Rostedt
2018-09-14 1:12 ` Steven Rostedt
2018-09-14 1:55 ` Sergey Senozhatsky
2018-06-21 8:29 ` Sergey Senozhatsky
2018-06-20 9:30 ` Dmitry Vyukov
2018-06-20 11:19 ` Sergey Senozhatsky
2018-06-20 11:25 ` Dmitry Vyukov
2018-06-20 11:37 ` Fengguang Wu
2018-06-20 12:31 ` Dmitry Vyukov
2018-06-20 12:41 ` Fengguang Wu
2018-06-20 12:45 ` Dmitry Vyukov
2018-06-20 12:48 ` Fengguang Wu
2018-05-11 13:37 ` printk feature for syzbot? Steven Rostedt
2018-05-15 5:20 ` Sergey Senozhatsky
2018-05-15 14:39 ` Steven Rostedt
2018-05-11 11:02 ` [PATCH] printk: fix possible reuse of va_list variable Tetsuo Handa
2018-05-11 11:27 ` Sergey Senozhatsky
2018-05-17 11:57 ` Petr Mladek
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