From: daley <daleydeng@gmail.com>
To: linux-kernel@vger.kernel.org
Subject: Two question about kernel global function declaration and directory layout
Date: Mon, 03 Sep 2012 23:32:59 +0800 [thread overview]
Message-ID: <5044CDAB.4000902@gmail.com> (raw)
hi, everyone, I'm a big fan of the kernel, I was always being attracted
by its clean and intelligent design. I'm new to the mailing list and
this is my first post. I want to ask two basic question about kernel
which bother me a lot, I've googled a lot but nobody could give a
suitable answer .
The first one is about global function declaration, I was confused about
the usage of keyword "extern" before a global function which declared in
the header file. for example,
<include/linux/kernel.h>
extern long (*panic_blink)(int state);
__printf(1, 2)
void panic(const char *fmt, ...)
__noreturn __cold;
extern void oops_enter(void);
extern void oops_exit(void);
void print_oops_end_marker(void);
extern int oops_may_print(void);
void do_exit(long error_code)
__noreturn;
void complete_and_exit(struct completion *, long)
__noreturn;
the same thing also appeared on other header files a lot. To my
knowledge, there's no difference between whether has the "extern" before
global function, is this due to the legacy problem or have other meaning?
The second question is why not move the *sound* directory into the
*drivers* directory or put bigger subsystem out of drivers, since there
are more bigger subsystems(e.g. media, scsi) than sound?
Can anybody help?
Thanks.
--
daleydeng
Beijing, China
next reply other threads:[~2012-09-03 15:33 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-03 15:32 daley [this message]
2012-09-04 0:59 ` Two question about kernel global function declaration and directory layout Ryan Mallon
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=5044CDAB.4000902@gmail.com \
--to=daleydeng@gmail.com \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).