cvs commit: src/sys/conf files src/sys/fs/tmpfs tmpfs.h tmpfs_subr.c tmpfs_vnops.c src/sys/i386/i386 bios.c src/sys/ia64/ia64 efi.c sal.c src/sys/libkern memcmp.c src/sys/mips/mips support.S src/sys/sys libkern.h

[David O'Brien]

On Tue, Sep 23, 2008 at 07:56:11AM -0700, Sam Leffler wrote:
> David E. O'Brien wrote:
>> obrien      2008-09-23 14:45:10 UTC
>>   FreeBSD src repository
>>   Modified files:
>>     sys/conf             files     sys/fs/tmpfs         tmpfs.h 
>> tmpfs_subr.c tmpfs_vnops.c     sys/i386/i386        bios.c     
>> sys/ia64/ia64        efi.c sal.c     sys/mips/mips        support.S     
>> sys/sys              libkern.h   Added files:
>>     sys/libkern          memcmp.c   Log:
>>   SVN rev 183299 on 2008-09-23 14:45:10Z by obrien
>>     The kernel implemented 'memcmp' is an alias for 'bcmp'.  However, 
>> memcmp
>>   and bcmp are not the same thing.  'man bcmp' states that the return is
>>   "non-zero" if the two byte strings are not identical.  Where as,
>>   'man memcmp' states that the return is the "difference between the
>>   first two differing bytes (treated as unsigned char values" if the
>>   two byte strings are not identical.
>>     So provide a proper memcmp(9), but it is a C implementation not a 
>> tuned
>>   assembly implementation.  Therefore bcmp(9) should be preferred over 
>> memcmp(9).
>>    
> Given the performance difference this change should have been reviewed 
> before dumping it into the tree.

> I do not agree with this;

You do not agree with fixing a bug in our code?

> did you post it somewhere?

No.

-- 
-- David  (obrien at FreeBSD.org)