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* Make backend local tracking of buffer pins memory efficient.Andres Freund2014-08-30
| | | | | | | | | | | | | | | | | | | | | | | | Since the dawn of time (aka Postgres95) multiple pins of the same buffer by one backend have been optimized not to modify the shared refcount more than once. This optimization has always used a NBuffer sized array in each backend keeping track of a backend's pins. That array (PrivateRefCount) was one of the biggest per-backend memory allocations, depending on the shared_buffers setting. Besides the waste of memory it also has proven to be a performance bottleneck when assertions are enabled as we make sure that there's no remaining pins left at the end of transactions. Also, on servers with lots of memory and a correspondingly high shared_buffers setting the amount of random memory accesses can also lead to poor cpu cache efficiency. Because of these reasons a backend's buffers pins are now kept track of in a small statically sized array that overflows into a hash table when necessary. Benchmarks have shown neutral to positive performance results with considerably lower memory usage. Patch by me, review by Robert Haas. Discussion: 20140321182231.GA17111@alap3.anarazel.de
* pgindent run for 9.4Bruce Momjian2014-05-06
| | | | | This includes removing tabs after periods in C comments, which was applied to back branches, so this change should not effect backpatching.
* Update copyright for 2014Bruce Momjian2014-01-07
| | | | | Update all files in head, and files COPYRIGHT and legal.sgml in all back branches.
* Update copyrights for 2013Bruce Momjian2013-01-01
| | | | | Fully update git head, and update back branches in ./COPYRIGHT and legal.sgml files.
* Update copyright notices for year 2012.Bruce Momjian2012-01-01
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* Stamp copyrights for year 2011.Bruce Momjian2011-01-01
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* Remove cvs keywords from all files.Magnus Hagander2010-09-20
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* Update copyright for the year 2010.Bruce Momjian2010-01-02
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* Add an EXPLAIN (BUFFERS) option to show buffer-usage statistics.Robert Haas2009-12-15
| | | | | | | | This patch also removes buffer-usage statistics from the track_counts output, since this (or the global server statistics) is deemed to be a better interface to this information. Itagaki Takahiro, reviewed by Euler Taveira de Oliveira.
* Update copyright for 2009.Bruce Momjian2009-01-01
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* Allow ShowBufferUsage() to report the number of reads/writes that haveTom Lane2008-09-17
| | | | | | | occurred to temporary files. This replaces the unused NDirectFileRead/NDirectFileWrite counters. Itagaki Takahiro
* Update copyrights in source tree to 2008.Bruce Momjian2008-01-01
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* Update CVS HEAD for 2007 copyright. Back branches are typically notBruce Momjian2007-01-05
| | | | back-stamped for this.
* Update copyright for 2006. Update scripts.Bruce Momjian2006-03-05
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* Standard pgindent run for 8.1.Bruce Momjian2005-10-15
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* Convert the arithmetic for shared memory size calculation from 'int'Tom Lane2005-08-20
| | | | | | | | | | | to 'Size' (that is, size_t), and install overflow detection checks in it. This allows us to remove the former arbitrary restrictions on NBuffers etc. It won't make any difference in a 32-bit machine, but in a 64-bit machine you could theoretically have terabytes of shared buffers. (How efficiently we could manage 'em remains to be seen.) Similarly, num_temp_buffers, work_mem, and maintenance_work_mem can be set above 2Gb on a 64-bit machine. Original patch from Koichi Suzuki, additional work by moi.
* Remove BufferBlockPointers array in favor of a base + (bufnum) * BLCKSZTom Lane2005-08-12
| | | | | | | | computation. On modern machines this is as fast if not faster, and we don't have to clog the CPU's L2 cache with a tens-of-KB pointer array. If we ever decide to adopt a more dynamic allocation method for shared buffers, we'll probably have to revert this patch, but in the meantime we might as well save a few bytes and nanoseconds. Per Qingqing Zhou.
* Cause ShutdownPostgres to do a normal transaction abort during backendTom Lane2005-08-08
| | | | | | | | exit, instead of trying to take shortcuts. Introduce some additional shutdown callback routines to eliminate kluges like having ProcKill be responsible for shutting down the buffer manager. Ensure that the order of operations during shutdown is predictable and what you would expect given the module layering.
* Split the shared-memory array of PGPROC pointers out of the sinvalTom Lane2005-05-19
| | | | | | communication structure, and make it its own module with its own lock. This should reduce contention at least a little, and it definitely makes the code seem cleaner. Per my recent proposal.
* Replace the BufMgrLock with separate locks on the lookup hashtable andTom Lane2005-03-04
| | | | | | | | the freelist, plus per-buffer spinlocks that protect access to individual shared buffer headers. This requires abandoning a global freelist (since the freelist is a global contention point), which shoots down ARC and 2Q as well as plain LRU management. Adopt a clock sweep algorithm instead. Preliminary results show substantial improvement in multi-backend situations.
* Ensure that all details of the ARC algorithm are hidden within freelist.c.Tom Lane2005-02-03
| | | | | This refactoring does not change any algorithms or data structures, just remove visibility of the ARC datastructures from other source files.
* Tag appropriate files for rc3PostgreSQL Daemon2004-12-31
| | | | | | | | Also performed an initial run through of upgrading our Copyright date to extend to 2005 ... first run here was very simple ... change everything where: grep 1996-2004 && the word 'Copyright' ... scanned through the generated list with 'less' first, and after, to make sure that I only picked up the right entries ...
* Remove BufferLocks[] array in favor of a single pointer to the bufferTom Lane2004-10-16
| | | | | | (if any) currently waited for by LockBufferForCleanup(), which is all that we were using it for anymore. Saves some space and eliminates proportional-to-NBuffers slowdown in UnlockBuffers().
* Pgindent run for 8.0.Bruce Momjian2004-08-29
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* Update copyright to 2004.Bruce Momjian2004-08-29
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* Code review for EXEC_BACKEND changes. Reduce the number of #ifdefs byTom Lane2004-05-28
| | | | | | | | | | | about a third, make it work on non-Windows platforms again. (But perhaps I broke the WIN32 code, since I have no way to test that.) Fold all the paths that fork postmaster child processes to go through the single routine SubPostmasterMain, which takes care of resurrecting the state that would normally be inherited from the postmaster (including GUC variables). Clean up some places where there's no particularly good reason for the EXEC and non-EXEC cases to work differently. Take care of one or two FIXMEs that remained in the code.
* Make LocalRefCount and PrivateRefCount arrays of int32, rather than long.Neil Conway2004-04-22
| | | | This saves a small amount of per-backend memory for LP64 machines.
* Another round of code cleanup on bufmgr. Use BM_VALID flag to keep trackTom Lane2004-04-21
| | | | | | | | | of whether we have successfully read data into a buffer; this makes the error behavior a bit more transparent (IMHO anyway), and also makes it work correctly for local buffers which don't use Start/TerminateBufferIO. Collapse three separate functions for writing a shared buffer into one. This overlaps a bit with cleanups that Neil proposed awhile back, but seems not to have committed yet.
* Code review for ARC patch. Eliminate static variables, improve handlingTom Lane2004-04-19
| | | | | | | | of VACUUM cases so that VACUUM requests don't affect the ARC state at all, avoid corner case where BufferSync would uselessly rewrite a buffer that no longer contains the page that was to be flushed. Make some minor other cleanups in and around the bufmgr as well, such as moving PinBuffer and UnpinBuffer into bufmgr.c where they really belong.
* Fixed bug where FlushRelationBuffers() did call StrategyInvalidateBuffer()Jan Wieck2004-02-12
| | | | | | | | | | | for already empty buffers because their buffer tag was not cleard out when the buffers have been invalidated before. Also removed the misnamed BM_FREE bufhdr flag and replaced the checks, which effectively ask if the buffer is unpinned, with checks against the refcount field. Jan
* Adjusted calculation of shared memory requirements to newJan Wieck2004-01-15
| | | | | | ARC buffer replacement strategy. Jan
* This patch is the next step towards (re)allowing fork/exec.Bruce Momjian2003-12-20
| | | | Claudio Natoli
* I posted some bufmgr cleanup a few weeks ago, but it conflicted withNeil Conway2003-12-14
| | | | | | | | | | | | | | | | | | | | | | | | some concurrent changes Jan was making to the bufmgr. Here's an updated version of the patch -- it should apply cleanly to CVS HEAD and passes the regression tests. This patch makes the following changes: - remove the UnlockAndReleaseBuffer() and UnlockAndWriteBuffer() macros, and replace uses of them with calls to the appropriate functions. - remove a bunch of #ifdef BMTRACE code: it is ugly & broken (i.e. it doesn't compile) - make BufferReplace() return a bool, not an int - cleanup some logic in bufmgr.c; should be functionality equivalent to the previous code, just cleaner now - remove the BM_PRIVATE flag as it is unused - improve a few comments, etc.
* $Header: -> $PostgreSQL Changes ...PostgreSQL Daemon2003-11-29
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* 2nd try for the ARC strategy.Jan Wieck2003-11-13
| | | | | | | | | I added a couple more Assertions while tracking down the exact cause of the former bug. All 93 regression tests pass now. Jan
* ARC strategy backed out ... sorryJan Wieck2003-11-13
| | | | Jan
* Replacement of the buffer replacement strategy with an ARCJan Wieck2003-11-13
| | | | | | algorithm adopted for PostgreSQL. Jan
* Update copyrights to 2003.Bruce Momjian2003-08-04
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* Remove ShutdownBufferPoolAccess exit callback, and do the work inTom Lane2002-09-25
| | | | | | | | | ProcKill instead, where we still have a PGPROC with which to wait on LWLocks. This fixes 'can't wait without a PROC structure' failures occasionally seen during backend shutdown (I'm surprised they weren't more frequent, actually). Add an Assert() to LWLockAcquire to help catch any similar mistakes in future. Fix failure to update MyProcPid for standalone backends and pgstat processes.
* pgindent run.Bruce Momjian2002-09-04
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* Remove sys/types.h in files that include postgres.h, and hence c.h,Bruce Momjian2002-09-02
| | | | because c.h has sys/types.h.
* Restructure local-buffer handling per recent pghackers discussion.Tom Lane2002-08-06
| | | | | | | | | | | | | | The local buffer manager is no longer used for newly-created relations (unless they are TEMP); a new non-TEMP relation goes through the shared bufmgr and thus will participate normally in checkpoints. But TEMP relations use the local buffer manager throughout their lifespan. Also, operations in TEMP relations are not logged in WAL, thus improving performance. Since it's no longer necessary to fsync relations as they move out of the local buffers into shared buffers, quite a lot of smgr.c/md.c/fd.c code is no longer needed and has been removed: there's no concept of a dirty relation anymore in md.c/fd.c, and we never fsync anything but WAL. Still TODO: improve local buffer management algorithms so that it would be reasonable to increase NLocBuffer.
* Update copyright to 2002.Bruce Momjian2002-06-20
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* Remove some pre-WAL relics:Bruce Momjian2002-06-15
| | | | | | | | | SharedBufferChanged BufferRelidLastDirtied BufferTagLastDirtied BufferDirtiedByMe Manfred Koizar
* New pgindent run with fixes suggested by Tom. Patch manually reviewed,Bruce Momjian2001-11-05
| | | | initdb/regression tests pass.
* pgindent run on all C files. Java run to follow. initdb/regressionBruce Momjian2001-10-25
| | | | tests pass.
* Another round of cleanups for dynahash.c (maybe it's finally clean ofTom Lane2001-10-01
| | | | | | | | | portability issues). Caller-visible data structures are now allocated on MAXALIGN boundaries, allowing safe use of datatypes wider than 'long'. Rejigger hash_create API so that caller specifies size of key and total size of entry, not size of key and size of rest of entry. This simplifies life considerably since each number is just a sizeof(), and padding issues etc. are taken care of automatically.
* Implement new 'lightweight lock manager' that's intermediate betweenTom Lane2001-09-29
| | | | | | | | | 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.
* Implement LockBufferForCleanup(), which will allow concurrent VACUUMTom Lane2001-07-06
| | | | | to wait until it's safe to remove tuples and compact free space in a shared buffer page. Miscellaneous small code cleanups in bufmgr, too.
* pgindent run. Make it all clean.Bruce Momjian2001-03-22
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