to reference the spinlock variable, and specify "memory" as a clobber
operand to be sure gcc does not try to keep shared-memory values in
registers across a spinlock acquisition. Also tighten the S/390 asm
sequence, which was apparently written with only minimal study of the
gcc asm documentation. I have personally tested i386, ia64, ppc, hppa,
and s390 variants --- there is some small chance that I broke the others,
but I doubt it.
instruction in the s_lock() wait loop, and use test before test-and-set
in TAS() macro to avoid unnecessary bus traffic. Patch from Manfred
Spraul, reworked a bit by Tom.
that were broken, try to make layout of s_lock.h entries consistent,
use HAVE_SPINLOCKS in preference to HAS_TEST_AND_SET everywhere outside
s_lock.h itself.
that OS=hpux is the same as CPU=hppa. First steps at doing this.
With these patches, we still work on hppa with either gcc or HP's cc.
We might work on hpux/itanium with gcc, but I can't test it. Definitely
will not work on hpux/itanium with non-gcc compiler, for lack of spinlock
code.
>
> ... he is now about to write an inlined version that can go into
> s_lock.h . I'll send the new patch later on...
OK, here it comes:
An inlined version of tas(), that works for both, powerpc and
powerpc64. The patch is against 7.3b5 and passes the test suite on
both architectures.
Reinhard Max
during the regression test. The problem has been reproduced on two machine
but both of these are the same type of hardware and software. I also tried
to recreate the problem on other machines, on older version of AIX but I
couldn't.
After looked through pgsql-hackers mailing list, I focused on spin lock
issue to solve the problem. The easiest and may not be the best solution
for the problem is to give up HAS_TEST_AND_SET. This actually works.
One another and better solution for the problem is to use _check_lock() and
_clear_lock() as spin lock. Important thing here is to define S_UNLOCK()
with _clear_lock(). This will solve the so called "Compiler bug" issue
someone wrote on the mailing list.
We have some other API such as cs(), compare_and_swap() and fetch_and_or()
to do test and set on AIX, but any of these didn't solve my problem. I
wrote tiny testing program to see if we have any bug of these API of AIX,
but I couldn't see any problem except for compare_and_swap(). It seems that
you can not use compare_and_swap() for the purpose, as it would not work as
spin lock on any SMP machines I tested. I don't know the reason why cs()
nor fetch_and_or()/fetch_and_and() will not work with PostgreSQL on p690.
These worked with my testing program on all machines I tested.
Tomoyuki Niijima
As proof of concept, provide an alternate implementation based on POSIX
semaphores. Also push the SysV shared-memory implementation into a
separate file so that it can be replaced conveniently.
existing lock manager and spinlocks: it understands exclusive vs shared
lock but has few other fancy features. Replace most uses of spinlocks
with lightweight locks. All remaining uses of spinlocks have very short
lock hold times (a few dozen instructions), so tweak spinlock backoff
code to work efficiently given this assumption. All per my proposal on
pghackers 26-Sep-01.
it does not support 64bit integers. AFAIK that's the default data type for
OIDs, so I am not surprised that this does not work. Use gcc instead.
BTW., 7.1 does not compile as is with gcc either, I believed the
required patches made it into the 7.1.1 release but obviously I missed
the deadline.
Since the ports mailing list does not seem to be archived I have attached
a copy of the patch (for 7.1 and 7.1.1).
I've just performed a build of a Watcom compiled version and found a couple
of bugs in the watcom specific part of that patch. Please use the attached
version instead.
Tegge, Bernd
waste of cycles on single-CPU machines, and of dubious utility on multi-CPU
machines too.
Tweak s_lock_stuck so that caller can specify timeout interval, and
increase interval before declaring stuck spinlock for buffer locks and XLOG
locks.
On systems that have fdatasync(), use that rather than fsync() to sync WAL
log writes. Ensure that WAL file is entirely allocated during XLogFileInit.
whitespace is unimportant in assembly code. Also, move VAX definition
of typedef slock_t to port header files to be like all the other ports.
Note that netbsd.h and openbsd.h are now identical, and I rather think
that freebsd.h is broken in the places where it doesn't agree --- but
I'll leave it to the freebsders to look at that.
for Alpha gcc case. For Alpha non-gcc case, replace use of
__INTERLOCKED_TESTBITSS_QUAD builtin with __LOCK_LONG_RETRY and
__UNLOCK_LONG. The former does not execute an MB instruction and
therefore was guaranteed not to work on multiprocessor machines.
The LOCK_LONG builtins produce code that is the same in all essential
details as the gcc assembler code.
assume that TAS() will always succeed the first time, even if the lock
is known to be free. Also, make sure that code will eventually time out
and report a stuck spinlock, rather than looping forever. Small cleanups
in s_lock.h, too.
IPC key assignment will now work correctly even when multiple postmasters
are using same logical port number (which is possible given -k switch).
There is only one shared-mem segment per postmaster now, not 3.
Rip out broken code for non-TAS case in bufmgr and xlog, substitute a
complete S_LOCK emulation using semaphores in spin.c. TAS and non-TAS
logic is now exactly the same.
When deadlock is detected, "Deadlock detected" is now the elog(ERROR)
message, rather than a NOTICE that comes out before an unhelpful ERROR.
* Makefile: Add more standard targets. Improve shell redirection in GNU
make detection.
* src/backend/access/transam/rmgr.c: Fix incorrect(?) C.
* src/backend/libpq/pqcomm.c (StreamConnection): Work around accept() bug.
* src/include/port/unixware.h: ...with help from here.
* src/backend/nodes/print.c (plannode_type): Remove some "break"s after
"return"s.
* src/backend/tcop/dest.c (DestToFunction): ditto.
* src/backend/nodes/readfuncs.c: Add proper prototypes.
* src/backend/utils/adt/numutils.c (pg_atoi): Cope specially with strtol()
setting EINVAL. This saves us from creating an extra set of regression test
output for the affected systems.
* src/include/storage/s_lock.h (tas): Correct prototype.
* src/interfaces/libpq/fe-connect.c (parseServiceInfo): Don't use variable
as dimension in array definition.
* src/makefiles/Makefile.unixware: Add support for GCC.
* src/template/unixware: same here
* src/test/regress/expected/abstime-solaris-1947.out: Adjust whitespace.
* src/test/regress/expected/horology-solaris-1947.out: Part of this file
was evidently missing.
* src/test/regress/pg_regress.sh: Fix shell. mkdir -p returns non-zero if
the directory exists.
* src/test/regress/resultmap: Add entries for Unixware.
> > For a while I though it might be because we are using an alpha TAS in
> > the spinlock rather than the old semaphore. I replaced our spinlock
> > with the standard one and it made no difference. We have been running
> > with our spinlock implementation for nearly 2 months on a production
> > database now without a hitch, so I think it is ok. Did I ever submit
> > any patches for the Alpha spinlock?
>
> Not that I recall. We did get some advice from some Alpha gurus at DEC
> who seemed to think the existing TAS code is OK. What was it that you
> felt needed to be improved?
The current code uses semaphores, which has the advantage that it works
well even on multi-processor machines, but the disadvantage that it is not
the fastest way possible. Writing a spinlock on Alpha for SMP machines is
very difficult, as you need to deal with memory barriers. A real mess. But
then one of the people at Compaq pointed out to us that there is a
ready-made routine on Alpha. We implemented it with the two patches below.
I ran tests with lots of parallel back-ends and got around a 10% speed
increase. I include the two patches. Perhaps some of the other people
running Tru64 can have a look at these as well.
Cheers,
Adriaan Joubert
PostgreSQL-7.0.2 run on Linux for the Intel-IA64 architecture. It also
fixes a bug in the configure scripts that caused configure to fail on
the fcntl(F_SETLK) test.
This fix triggered a bug in the fcntl(F_SETLK) code of the Linux
kernel when used on unix domain sockets resulting in postmaster to
segfault immediately after startup. There is a fix available and
included in the kernel that will be on SuSE Linux 7.0, but kernels <=
2.2.16 still have this bug.
Reinhard Max
spin-locks. Notice that it's now inline assembler in s_lock.h,
rather than seperate code in s_lock.c. It also shrank a little
bit... Just rip out the S_LOCK() define and insert the tas() inline
function. Please let me know if there are any problems with it.
Jon Buller
1. The UnixWare tas macro was reformatted (by indent or it like?) which caused
it to break. The asm macro construct is very particular about the %mem
construct -- it has to start in column 1.
2. When compiling libpq++, g++ was used even if configure found the C++ com-
piler to be CC.
3. When compiling libpq++, '-Wno-error' was added to CXXFLAGS, even if the
compiler wasn't g++.
Billy G. Allie
Summary of changes:
In pqcomm.h, use the SUN_LEN macro if it is defined to calculate
the size of the sockaddr_un structure.
In unixware.h, drop the use of the UNIXWARE macro. Everything can
be handled with the USE_UNIVEL_CC and DISABLE_COMPLEX_MACRO macros.
In s_lock.h, remove the reference to the UNIXWARE macro (see above).
In the unixware template, add the YFLAGS:-d line.
In various makefile templates, add (or cleanup) unixware and univel
port specific information.
-- Billy G. Allie
in a more readable form. -- I am submitting the following patches
to the June 6, 1998 snapshot of PostgreSQL. These patches implement
a port of PostgreSQL to SCO UnixWare 7, and updates the Univel port
(UnixWare 2.x). The patched files, and the reason
for the patch are:
File Reason for the patch ---------------
---------------------------------------------------------------
src/backend/port/dynloader/unixware.c src/backend/port/dynloader/unixware.h
src/include/port/unixware.h src/makefiles/Makefile.unixware
src/template/unixware
Created for the UNIXWARE port.
src/include/port/univel.h
Modifed this file to work with the changes made to
s_lock.[ch].
src/backend/storage/buffer/s_lock.c src/include/storage/s_lock.h
Moved the UNIXWARE (and Univel) tas() function from
s_lock.c to s_lock.h. The UnixWare compiler asm
construct is treated as a macro and needs to be in
the s_lock.h file. I also reworked the tas()
function to correct some errors in the code.
src/include/version.h.in
The use of the ## operator with quoted strings in
the VERSION macro caused problems with the UnixWare
C compiler. I removed the ## operators since they
were not needed in this case. The macro expands
into a sequence of quoted strings that will be
concatenated by any ANSI C compiler.
src/config.guess
This script was modified to recognize SCO UnixWare
7.
src/configure src/configure.in
The configure script was modified to recognize SCO
UnixWare 7.
Billy G. Allie
NS32K machine I contributed. In any case, I now have postgresql-6.3
running again on NetBSD/pc532, a NS32532 machine. The following
changes are needed relative to the src directory. (It looks like
support was partially removed when the files were moved from the
src/backend/storage/.... tree to the src/include tree.)
If you need me to get a current development version of postgresql
for this change let me know. Also, let me know if this code needs
updating due to another code movement that deleted the old NS32K
support.
Thank you.
Phil Nelson
GCC, the inner "#if defined(__GNUC__)" can just be omitted in that
architecture's block.
The existing arrangement with an outer "#if defined(__GNUC__)"
doesn't have any obvious benefit, and it encourages missed cases
like this one.
BTW, I'd suggest making the definition of clear_lock for HPUX be
static const slock_t clear_lock = {{-1, -1, -1, -1}};
The extra braces are needed to suppress warnings from gcc, and
declaring it const just seems like good practice.
regards, tom lane
but as I don't have access to a sparc for testing I just did what
I could. I am guessing here, but please apply the following to your
pgsql and let me know what happens. Also, cd to src/storage/buffer
and do 'make s_lock_test' as well.
David Gould
This incorporates all the precedeing patches and emailed suggestions
and the results of the performance testing I posted last week. I
would like to get this tested on as many platforms as possible so
I can verify it went in correctly (as opposed to the horrorshow
last time I sent in a patch).
Once this is confirmed, I will make a tarball of files that can be
dropped into a 6.3.2 source tree as a few people have asked for
this in 6.3.2 as well.
David Gould
Attached patch will add a version() function to Postges, e.g.
template1=> select version();
version
------------------------------------------------------------
PostgreSQL 6.3.2 on i586-pc-linux-gnu, compiled by gcc 2.8.1
(1 row)
Ok, I have finally gotten all of the defines for Dec/Alpha and
Linux/Alpha sorted out as Marc asked. There is no longer any need for
'-Dalpha' or '-Dlinuxalpha' in either the Dec/Alpha or the Linux/Alpha
template files (./src/template/{alpha,linuxalpha}). I have replaced every
instance of 'alpha' or '__alpha__' with '__alpha', as that appears to be
the common symbol between C compilers on both operating systems (RH4.2 &
DecUnix 4.0b) for alpha.
The following patches will allow postgreSQL 6.3 to compile and run on a
UNIXWARE 2.1.2 system with the native C compiler with the following library
change:
The alloca function must be copied from the libucb.a archive and added
to the libgen.a archive.
Also, the GNU flex program is needed to successfully build postgreSQL.
Only occurrs in
src/include/storage/s_lock.h:#if defined(__AIX)
src/include/utils/dt.h:#if defined(__AIX)
src/include/utils/nabstime.h:#if defined(__AIX)
Simply delete one underscore, only occurs once per file, so no patch.
Apart from this Makefile hack, all I've done is to make dynamically
loaded code modules fail properly (as was already done for __mips__,
although I think this is too loose: I believe NetBSD for the pmax can
do dynamic linking), and to add test-and-set lock handling. As Bruce
suggested, this is done in a maximally efficient inlined way: I was
not aware that this code was so important, speed-wise.
The attached patches will allow postgreSQL to compile successfully on SCO
UNIXWARE 2.1.x. The patches fix the following problems:
1. Configure did not properly recognize the UNIXWARE system as needing the
univel port. It used the sys4 port.
2. Configure did not properly process the CC flag in the template file.
3. There was no working test and set locking implementation for the native
UNIXWARE compiler.
4. The test and set locking used for Intel X86 that was selected by defining
NEED_I386_TAS_ASM could fail in a multi-processor environment.
5. The makefiles for libpq and libpgtcl did not make a shared library for
the univel port.
Bruce Momjian
Tom Lane
PostgreSQL Daemon
Peter Eisentraut
Thomas G. Lockhart
Tatsuo Ishii
Vadim B. Mikheev
Marc G. Fournier