xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

[PATCH] sparc32 rwlock fix

Browse Source 
read_trylock() is broken on sparc32 (doesn't build and didn't work
right, actually).  Proposed fix:

 - make "writer holds lock" distinguishable from "reader tries to grab
   lock"

 - have __raw_read_trylock() try to acquire the mutex (in LSB of lock),
   terminating spin if we see that there's writer holding it.  Then do
   the rest as we do in read_lock().

Thanks to Ingo for discussion...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Al Viro
2006-10-08 14:32:15 +01:00
committed by Linus Torvalds
parent 6d24c8dc2e
commit 7a39f52202
3 changed files with 50 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
arch/sparc/kernel/sparc_ksyms.c
View File

@@ -87,6 +87,7 @@ extern void ___set_bit(void);
extern void ___clear_bit(void);
extern void ___change_bit(void);
extern void ___rw_read_enter(void);
extern void ___rw_read_try(void);
extern void ___rw_read_exit(void);
extern void ___rw_write_enter(void);
@@ -104,8 +105,9 @@ extern unsigned _Urem(unsigned, unsigned);
EXPORT_SYMBOL(sparc_cpu_model);
EXPORT_SYMBOL(kernel_thread);
#ifdef CONFIG_SMP
// XXX find what uses (or used) these.
// XXX find what uses (or used) these. AV: see asm/spinlock.h
EXPORT_SYMBOL(___rw_read_enter);
EXPORT_SYMBOL(___rw_read_try);
EXPORT_SYMBOL(___rw_read_exit);
EXPORT_SYMBOL(___rw_write_enter);
#endif