(--with-maxbackends). Add a postmaster switch (-N backends) that allows
the limit to be reduced at postmaster start time. (You can't increase it,
sorry to say, because there are still some fixed-size arrays.)
Grab the number of semaphores indicated by min(MAXBACKENDS, -N) at
postmaster startup, so that this particular form of bogus configuration
is exposed immediately rather than under heavy load.
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
> sinval.patch
>
> fixes a problem in SI cache which causes table overflow if some
> backend is idle for a long time while other backends keep adding
> entries.
> It uses the new signal handling implemented in tprintf.patch.
> I have also increacasesed the max number of backends from 32 to 64
> and the table size from 1000 to 5000.
> I don't know if anybody is working on SI, but until another
> solution is found this patch fixes the problem. I have received
> messages from other people reporting the same problem which I
> fixed many months ago.
lock.patch
I have rewritten lock.c cleaning up the code and adding better
assert checking I have also added some fields to the lock and
xid tags for better support of user locks. There is also a new
function which returns an array of pids owning a lock.
I'm using this code from over six months and it works fine.
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
no longer returns buffer pointer, can be gotten from scan;
descriptor; bootstrap can create multi-key indexes;
pg_procname index now is multi-key index; oidint2, oidint4, oidname
are gone (must be removed from regression tests); use System Cache
rather than sequential scan in many places; heap_modifytuple no
longer takes buffer parameter; remove unused buffer parameter in
a few other functions; oid8 is not index-able; remove some use of
single-character variable names; cleanup Buffer variables usage
and scan descriptor looping; cleaned up allocation and freeing of
tuples; 18k lines of diff;
calls. Outside a transaction, the backend detects them as buffer
leaks; it sends a NOTICE, and frees them. This sometimes cause a
segmentation fault (at least on Linux). These indexes are initialized
on the first lo_read/lo_write/lo_tell call, and (normally) closed
on a lo_close call. Thus the buffer leaks appear when lo direct
access functions are used, and not with lo_import/lo_export functions
(libpq version calls lo_close before ending the command, and the
backend version uses another path).
The included patches (against recent snapshot, and against 6.3.2)
cause indexes to be closed on transaction end (that is on explicit
'END' statment, or on command termination outside trasaction blocks),
thus preventing the buffer leaks while increasing performance inside
transactions. Some (all?) 'classic' memory leaks are also removed.
I hope it will be ok.
--- Pascal ANDRE, graduated from Ecole Centrale Paris andre@via.ecp.fr
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.
==========================================
What follows is a set of diffs that cleans up the usage of BLCKSZ.
As a side effect, the person compiling the code can change the
value of BLCKSZ _at_their_own_risk_. By that, I mean that I've
tried it here at 4096 and 16384 with no ill-effects. A value
of 4096 _shouldn't_ affect much as far as the kernel/file system
goes, but making it bigger than 8192 can have severe consequences
if you don't know what you're doing. 16394 worked for me, _BUT_
when I went to 32768 and did an initdb, the SCSI driver broke and
the partition that I was running under went to hell in a hand
basket. Had to reboot and do a good bit of fsck'ing to fix things up.
The patch can be safely applied though. Just leave BLCKSZ = 8192
and everything is as before. It basically only cleans up all of the
references to BLCKSZ in the code.
If this patch is applied, a comment in the config.h file though above
the BLCKSZ define with warning about monkeying around with it would
be a good idea.
Darren darrenk@insightdist.com
(Also cleans up some of the #includes in files referencing BLCKSZ.)
==========================================
Reply-To: hackers@hub.org, Dan McGuirk <mcguirk@indirect.com>
To: hackers@hub.org
Subject: [HACKERS] tmin writeback optimization
I was doing some profiling of the backend, and noticed that during a certain
benchmark I was running somewhere between 30% and 75% of the backend's CPU
time was being spent in calls to TransactionIdDidCommit() from
HeapTupleSatisfiesNow() or HeapTupleSatisfiesItself() to determine that
changed rows' transactions had in fact been committed even though the rows'
tmin values had not yet been set.
When a query looks at a given row, it needs to figure out whether the
transaction that changed the row has been committed and hence it should pay
attention to the row, or whether on the other hand the transaction is still
in progress or has been aborted and hence the row should be ignored. If
a tmin value is set, it is known definitively that the row's transaction
has been committed. However, if tmin is not set, the transaction
referred to in xmin must be looked up in pg_log, and this is what the
backend was spending a lot of time doing during my benchmark.
So, implementing a method suggested by Vadim, I created the following
patch that, the first time a query finds a committed row whose tmin value
is not set, sets it, and marks the buffer where the row is stored as
dirty. (It works for tmax, too.) This doesn't result in the boost in
real time performance I was hoping for, however it does decrease backend
CPU usage by up to two-thirds in certain situations, so it could be
rather beneficial in high-concurrency settings.
Subject: [HACKERS] linux/alpha patches
These patches lay the groundwork for a Linux/Alpha port. The port doesn't
actually work unless you tweak the linker to put all the pointers in the
first 32 bits of the address space, but it's at least a start. It
implements the test-and-set instruction in Alpha assembly, and also fixes
a lot of pointer-to-integer conversions, which is probably good anyway.
