About 34 system calls need work (with time changes), approximately 16 without time changes. I've included a summary at the end.
The questions before us: * What to do about time representation. * Whether to create a new syscall vector or use the existing vector. I have thought long and hard about this and I now believe that we should keep our existing vector, even though it's become a real mess, at least through the release. This will also allow us to convert to a 64 bit time representation without blowing anything up. The original API calls would of course remain valid. wait4() -> wait464() *stat() -> *stat64() getrusage() -> getrusage64() getfsstat() -> getfsstat64() *statfs() -> *statfs64() *itimer() -> *itimer64() select() -> select64() gettimeofday() -> gettimeofday64() settimeofday() -> settimeofday64() *times() -> *times64() adjtime() -> adjtime64() quotactl() -> quotactl64() CREATE sleep64() (takes timeval64) typedef int64_t time64_t; struct timeval64 { time64_t tv_sec; int64_t tv_frac; /* N/2^63 fractional */ }; typedef struct timeval64 timespec64; struct itimerval64 { struct timeval64 it_interval; struct timeval64 it_value; int64_t it_resolution; /* N/2^63 fractional (ro) */ } #define TIMEFRAC 0x4000000000000000LL I understand some people may want this to be unsigned and 0xF[63] or 0x7F[62] but this makes the fractional value an imperfect representation in both base 10 and base 2 and its a good idea to make it a perfect representation in at least base 10 or base 2. Also, divider logic is far faster with fewer '1' bits. In terms of signed verses unsigned it is far easier to use a signed value here in regards to program logic and useage and, additionally, being able to represent negative times is a useful abstraction even if the syscalls do not particularly need the capability. In regards to normalizing the API such that a call to stat() should actually be a call to stat64(), I believe a compiler option may be the best way to go. The compiler option would simply pre-set a #define and our includes would #define-rename the functions to present a normalized API to those programs that can handle it. Example: gcc --unix64 (sets __UNIX_API64__) gcc --unix32 (unsets __UNIX_API64__) (default) Then our system include files would do this (in appropriate places): #ifdef __UNIX_API64__ #define stat stat64 #define ... (etc) #define time_t time64_t #define timeval timeval64 #endif Amoung other things this should hopefully make any issues that come up debuggable by causing the compiler to generate warnings when prototypes do not match up. EVENTUAL GOAL The eventual goal would then be to compile our entire source tree with --unix64 through a release or two, and then, eventually (perhaps two years down the line) we would make --unix64 the default. TIMEVAL64 ISSUES Now there is a fairly serious issue with using fractional seconds, and that is that you cannot use the representation additively. That is, you cannot represent '100ns' in the structure and then add thousands of structures together and get the result you expect because 100ns cannot be represented exactly with this method. This is the same problem that financial systems have when they try to use floating point (e.g. 'double') to add monetary amounts together. If you do not round each intermediate result to the required resolution errors can creep into long calculations. As long as people understand this problem I believe the format is reasonable. -Matt Matthew Dillon <[EMAIL PROTECTED]> (Matt's summary of syscall changes) wait4 extend rusage elements to 64 bits getrusage extend rusage elements to 64 bits getfsstat extend f_blocks, f_bfree, f_bavail, f_files, f_ffree, f_syncwrites, f_asyncwrites, f_syncreads, f_asyncreads to 64 bits, add any additional fields required by Kirk. *statfs various internal fields and time *stat ino_t -> 64 bits, time fields. What about st_gen ? *itimer itimerval contains timeval (also, add an ITIMER_HIRES feature) select timeval passed gettimeofday timeval passed settimeofday timeval passed *times timeval passed adjtime timeval passed quotactl extend dqblk structure to 64 bit limits ntp* Do any of the NTP API elements need to be extended? ntp_adjtime(), ntp_gettime() (well, the sysctl anyway) clock_gettime timespec passed clock_settime timespec passed clock_getres timespec passed nanosleep timespec passed (new function: sleep64()) To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-hackers" in the body of the message