Dear David,
During my work on NOMMU system (mm/nommu.c), I saw definition and
usage of kenter/kleave/kdebug macros. These macros are compiled as
empty because of "#if 0" construction.
45 #if 0
46 #define kenter(FMT, ...) \
47 printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
48 #define kleave(FMT, ...) \
49 printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
50 #define kdebug(FMT, ...) \
51 printk(KERN_DEBUG "xxx" FMT"yyy\n", ##__VA_ARGS__)
52 #else
53 #define kenter(FMT, ...) \
54 no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
55 #define kleave(FMT, ...) \
56 no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
57 #define kdebug(FMT, ...) \
58 no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
59 #endif
This code was changed in 2009 [1] and similar definitions can be found
in 9 other files [2]. The protection of these definitions is slightly
different. There are places with "#if 0" protection and others with
"#if defined(__KDEBUG)" protection. __KDEBUG is supposed to be
inserted by GCC.
My question is how we should handle such duplicated debug print code?
As possible solutions, I see five options:
1. Leave it as is.
2. Move it to general include file (for example linux/printk.h) and
commonize the output to be consistent between different kdebug users.
3. Add CONFIG_*_DEBUG definition for every kdebug user.
4. Move everything to "#if 0" construction.
5. Move everything to "#if defined(__KDEBUG)" construction.
What do you think?
[1] commit 8feae13110d60cc6287afabc2887366b0eb226c2
Author: David Howells <dhowells@xxxxxxxxxx>
Date: Thu Jan 8 12:04:47 2009 +0000
[2] List of all files there kdebug was defined:
* arch/mn10300/kernel/mn10300-serial.c
* arch/mn10300/mm/misalignment.c
* fs/cachefiles/internal.h
* fs/afs/internal.h
* fs/fscache/internal.h
* fs/binfmt_elf_fdpic.c
* kernel/cred.c
* mm/nommu.c
* net/rxrpc/ar-internal.h
* security/keys/internal.h
Thank you.
--
Leon Romanovsky | Independent Linux Consultant
www.leon.nu | leon@xxxxxxx
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>