Thread
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Re: Fw: Fw: bad performance on irix
Robert E. Bruccoleri <bruc@stone.congenomics.com> — 2002-03-18T21:04:02Z
Dear Tom, The evidence is from the Process Activity Recorder, an Irix utility similar to strace the reports syscall usage. A number of semop's are performed in the operation of backend. Luis can send you specifics. --Bob Luis Alberto Amigo Navarro writes: > > > ----- Original Message ----- > From: "Tom Lane" <tgl@sss.pgh.pa.us> > To: "Luis Alberto Amigo Navarro" <lamigo@atc.unican.es> > Cc: <pgsql-hackers@postgresql.org>; "Robert E. Bruccoleri" > <bruc@stone.congenomics.com> > Sent: Monday, March 18, 2002 5:36 PM > Subject: Re: Fw: [HACKERS] bad performance on irix > > > > "Luis Alberto Amigo Navarro" <lamigo@atc.unican.es> forwards: > > >> It's using the spinlocks > > >> for some locks, but semaphores for others. > > > > That doesn't make any sense to me. For one thing, if HAS_TEST_AND_SET > > is defined in the config header, the executable will just plain fail to > > build if there's no tas implementation, because lmgr/spin.c won't be > > compiled. And I sure don't see how some of the locks might be > > implemented one way and some the other. > > > > Which ones do you think are being implemented as semaphores, and what's > > your evidence? > > > > regards, tom lane > > > > ---------------------------(end of broadcast)--------------------------- > > TIP 5: Have you checked our extensive FAQ? > > > > http://www.postgresql.org/users-lounge/docs/faq.html > > > > +-----------------------------+------------------------------------+ | Robert E. Bruccoleri, Ph.D. | email: bruc@acm.org | | P.O. Box 314 | URL: http://www.congen.com/~bruc | | Pennington, NJ 08534 | | +-----------------------------+------------------------------------+
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Re: Fw: Fw: bad performance on irix
Luis Alberto Amigo Navarro <lamigo@atc.unican.es> — 2002-03-20T11:53:01Z
Hi all There is no doubt, in fact it uses test_and _set, but it is still doing a lot of semops, I send u and extract from another execution, it is 6 streams of read-only queries+a stream of inserts and deletes(with 5 sec between each stream)+a stream of vacuum on modified tables each 10 secs. Thanks and regards
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Re: Fw: Fw: bad performance on irix
Luis Alberto Amigo Navarro <lamigo@atc.unican.es> — 2002-03-20T16:48:09Z
Hi all: again on performance, here is an extract from an 8 read-only queries, notice that total time is 179s and it is expending about 80secs only in semaphores Isn't there any other way to improve ipc-locks? thanks and regards.
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Re: Fw: Fw: bad performance on irix
igor.kovalenko@motorola.com — 2002-03-20T20:33:52Z
Makes me wonder... perhaps now someone will be convinced to take a look at the POSIX IPC patch. On some platforms (not on Linux I am afraid) POSIX mutexes might be quite a bit faster than SYSV semaphores. Luis Alberto Amigo Navarro wrote: > > Hi all: > again on performance, here is an extract from an 8 read-only queries, notice > that total time is 179s and it is expending about 80secs only in semaphores > Isn't there any other way to improve ipc-locks? > thanks and regards. > > ---------------------------(end of broadcast)--------------------------- > TIP 5: Have you checked our extensive FAQ? > > http://www.postgresql.org/users-lounge/docs/faq.html
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Re: Fw: Fw: bad performance on irix
Robert E. Bruccoleri <bruc@stone.congenomics.com> — 2002-03-20T21:52:57Z
Dear Igor, Igor Kovalenko writes: > Makes me wonder... perhaps now someone will be convinced to take a look > at the POSIX IPC patch. On some platforms (not on Linux I am afraid) > POSIX mutexes might be quite a bit faster than SYSV semaphores. Yes, but on the SGI platform, the MIPS test_and_set instructions are really fast and should be used. +-----------------------------+------------------------------------+ | Robert E. Bruccoleri, Ph.D. | email: bruc@acm.org | | P.O. Box 314 | URL: http://www.congen.com/~bruc | | Pennington, NJ 08534 | | +-----------------------------+------------------------------------+
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Re: Fw: Fw: bad performance on irix
igor.kovalenko@motorola.com — 2002-03-20T22:18:57Z
I am confused to hell. I always thought MIPS does NOT have TAS instruction ;) "Robert E. Bruccoleri" wrote: > > Dear Igor, > > Igor Kovalenko writes: > > > Makes me wonder... perhaps now someone will be convinced to take a look > > at the POSIX IPC patch. On some platforms (not on Linux I am afraid) > > POSIX mutexes might be quite a bit faster than SYSV semaphores. > > Yes, but on the SGI platform, the MIPS test_and_set instructions are > really fast and should be used. > > +-----------------------------+------------------------------------+ > | Robert E. Bruccoleri, Ph.D. | email: bruc@acm.org | > | P.O. Box 314 | URL: http://www.congen.com/~bruc | > | Pennington, NJ 08534 | | > +-----------------------------+------------------------------------+
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Re: Fw: Fw: bad performance on irix
Robert E. Bruccoleri <bruc@stone.congenomics.com> — 2002-03-20T22:30:28Z
Dear Igor, > I am confused to hell. I always thought MIPS does NOT have TAS > instruction ;) On the SGI platform, there are very high speed implementations of test and set which allow large number of processes to safely and quickly access shared memory. SGI has a hardware team that specifies MIPS processor variants that are used in their servers so the machines can scale. I've tried to get SGI interested in putting some internal engineering effort to improve PostgreSQL performance on operations which could benefit from its shared memory parallel architecture (like index creation and sorting), but without success. +-----------------------------+------------------------------------+ | Robert E. Bruccoleri, Ph.D. | email: bruc@acm.org | | P.O. Box 314 | URL: http://www.congen.com/~bruc | | Pennington, NJ 08534 | | +-----------------------------+------------------------------------+
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Re: Fw: Fw: bad performance on irix
igor.kovalenko@motorola.com — 2002-03-20T22:32:38Z
Okay. Anyway, the semaphores are apparently used for purposes other than TAS. That can be made faster too, on platforms which support POSIX mutexes (shared between processes). "Robert E. Bruccoleri" wrote: > > Dear Igor, > > > I am confused to hell. I always thought MIPS does NOT have TAS > > instruction ;) > > On the SGI platform, there are very high speed implementations of test > and set which allow large number of processes to safely and quickly > access shared memory. SGI has a hardware team that specifies MIPS > processor variants that are used in their servers so the machines can > scale. > > I've tried to get SGI interested in putting some internal engineering > effort to improve PostgreSQL performance on operations which could > benefit from its shared memory parallel architecture (like index > creation and sorting), but without success. > > +-----------------------------+------------------------------------+ > | Robert E. Bruccoleri, Ph.D. | email: bruc@acm.org | > | P.O. Box 314 | URL: http://www.congen.com/~bruc | > | Pennington, NJ 08534 | | > +-----------------------------+------------------------------------+
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Re: Fw: Fw: bad performance on irix
Luis Alberto Amigo Navarro <lamigo@atc.unican.es> — 2002-03-21T08:35:02Z
> Makes me wonder... perhaps now someone will be convinced to take a look > at the POSIX IPC patch. On some platforms (not on Linux I am afraid) > POSIX mutexes might be quite a bit faster than SYSV semaphores. > Is there any current patch? Regards
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Re: Fw: Fw: bad performance on irix
Luis Alberto Amigo Navarro <lamigo@atc.unican.es> — 2002-03-21T08:48:11Z
I've done some meditions with timex, it uses sar(System activity register) to take workloads, it's not very relliable, but it allow us to see how it is been doing, it has been taken during an execution of a like tpc-h benchmark, it performs inserts, deletes(about 5% of the time of the execution) and a set of 8 continous streams of 22 read only queries, notice that it only gives idle time (not the cause of idle), notice semafores/sec is up to 2700!!!!!!! Regards 12:27:08 %usr %sys %intr %wio %idle %sbrk %wfs %wswp %wphy %wgsw %wfif 12:55:39 32 3 0 9 56 0 100 0 0 0 0 9% waiting for I/O which is 100% file system 12:27:08 device %busy avque r+w/s blks/s w/s wblks/s avwait avserv 12:55:39 dks0d5 0 0.0 0.0 0 0.0 0 0.0 0.0 dks1d1 1 3.1 0.7 19 0.7 16 27.8 15.0 dks1d2 0 1.0 0.0 0 0.0 0 0.0 13.3 dks1d3 0 0.0 0.0 0 0.0 0 0.0 0.0 dks1d4 23 15.3 9.1 1705 7.8 1553 519.7 24.8 12:27:08 bread/s lread/s %rcach bwrit/s lwrit/s wcncl/s %wcach pread/s pwrit/s 12:55:39 158 2372 93 1549 9072 1 83 0 0 93% of read cache hits and 83% of write chache hits 12:27:08 scall/s sread/s swrit/s fork/s exec/s rchar/s wchar/s 12:55:39 4618 181 126 0.18 0.06 648854 580354 syscalls averages 12:27:08 msg/s sema/s 12:55:39 0.00 2704.28 12:27:08 vflt/s dfill/s cache/s pgswp/s pgfil/s pflt/s cpyw/s steal/s rclm/s notice that there aren't page swaps, so idle is not waiting for paging 12:55:39 862.58 58.31 804.24 0.00 0.04 5.70 3.11 60.90 0.00 12:27:08 CPU %usr %sys %intr %wio %idle %sbrk %wfs %wswp %wphy %wgsw %wfif 12:55:39 0 25 3 0 8 63 0 100 0 0 0 0 per CPU usage 1 25 3 0 9 62 0 100 0 0 0 0 2 24 3 0 9 64 0 100 0 0 0 0 3 30 3 0 8 59 0 100 0 0 0 0 4 30 3 0 8 59 0 100 0 0 0 0 5 39 3 0 8 50 0 100 0 0 0 0 6 54 3 0 8 34 0 100 0 0 0 0 7 33 3 0 8 55 0 100 0 0 0 0 -
Re: Fw: Fw: bad performance on irix
igor.kovalenko@motorola.com — 2002-03-21T17:31:12Z
No, I've been told it is not gonna be considered for 7.2x and I shall wait till 7.3. Luis Alberto Amigo Navarro wrote: > > > Makes me wonder... perhaps now someone will be convinced to take a look > > at the POSIX IPC patch. On some platforms (not on Linux I am afraid) > > POSIX mutexes might be quite a bit faster than SYSV semaphores. > > > Is there any current patch? > Regards
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Re: Fw: Fw: bad performance on irix
Luis Alberto Amigo Navarro <lamigo@atc.unican.es> — 2002-03-21T18:30:31Z
Igor Kovalenko wrote: > No, I've been told it is not gonna be considered for 7.2x and I shall > wait till 7.3. > > Luis Alberto Amigo Navarro wrote: > > > > > Makes me wonder... perhaps now someone will be convinced to take a look > > > at the POSIX IPC patch. On some platforms (not on Linux I am afraid) > > > POSIX mutexes might be quite a bit faster than SYSV semaphores. > > > > > Is there any current patch? > > Regards > > ---------------------------(end of broadcast)--------------------------- > TIP 4: Don't 'kill -9' the postmaster I've been thinking, and I think it maybe possible that tuning kernel parameters could help, I'll keep you informed Thanks and regards
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Re: Fw: Fw: bad performance on irix
Christopher Kings-Lynne <chriskl@familyhealth.com.au> — 2002-03-22T01:59:57Z
Just remember that patches for 7.3 are being accepted at this very moment... Chris > -----Original Message----- > From: pgsql-hackers-owner@postgresql.org > [mailto:pgsql-hackers-owner@postgresql.org]On Behalf Of Igor Kovalenko > Sent: Friday, 22 March 2002 1:31 AM > To: Luis Alberto Amigo Navarro > Cc: bruc@acm.org; tgl@sss.pgh.pa.us; pgsql-hackers@postgresql.org > Subject: Re: Fw: Fw: [HACKERS] bad performance on irix > > > No, I've been told it is not gonna be considered for 7.2x and I shall > wait till 7.3. > > Luis Alberto Amigo Navarro wrote: > > > > > Makes me wonder... perhaps now someone will be convinced to > take a look > > > at the POSIX IPC patch. On some platforms (not on Linux I am afraid) > > > POSIX mutexes might be quite a bit faster than SYSV semaphores. > > > > > Is there any current patch? > > Regards > > ---------------------------(end of broadcast)--------------------------- > TIP 4: Don't 'kill -9' the postmaster >
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Re: Fw: Fw: bad performance on irix
Greg Copeland <greg@copelandconsulting.net> — 2002-03-22T16:51:32Z
On a side note, I thought I would mention that the Next Generation POSIX Threading (NGPT) Project (IBM -- http://www-124.ibm.com/developerworks/projects/pthreads) patches have just been accepted to the 2.5.x Linux kernel. A 2.4.x patch is also available. So, it may be possible that POSIX mutexes may be a performance reality for Linux sometime in the near future... Greg On Thu, 2002-03-21 at 19:59, Christopher Kings-Lynne wrote: > Just remember that patches for 7.3 are being accepted at this very moment... > > Chris > > > -----Original Message----- > > From: pgsql-hackers-owner@postgresql.org > > [mailto:pgsql-hackers-owner@postgresql.org]On Behalf Of Igor Kovalenko > > Sent: Friday, 22 March 2002 1:31 AM > > To: Luis Alberto Amigo Navarro > > Cc: bruc@acm.org; tgl@sss.pgh.pa.us; pgsql-hackers@postgresql.org > > Subject: Re: Fw: Fw: [HACKERS] bad performance on irix > > > > > > No, I've been told it is not gonna be considered for 7.2x and I shall > > wait till 7.3. > > > > Luis Alberto Amigo Navarro wrote: > > > > > > > Makes me wonder... perhaps now someone will be convinced to > > take a look > > > > at the POSIX IPC patch. On some platforms (not on Linux I am afraid) > > > > POSIX mutexes might be quite a bit faster than SYSV semaphores. > > > > > > > Is there any current patch? > > > Regards > > > > ---------------------------(end of broadcast)--------------------------- > > TIP 4: Don't 'kill -9' the postmaster > > > > ---------------------------(end of broadcast)--------------------------- > TIP 1: subscribe and unsubscribe commands go to majordomo@postgresql.org
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Re: Fw: Fw: bad performance on irix
igor.kovalenko@motorola.com — 2002-03-22T17:46:03Z
Does that mean I should redo patch for 7.3 as is, or you guys want it to go farther this time? The last version had compromises intended to make changes minimal... Also, does anyone from Darwin or BeOS camp care? You guys should not be working through emulation of SysV ugliness. If someone is listening, we could come up with a version suitable for you too... -- igor Christopher Kings-Lynne wrote: > > Just remember that patches for 7.3 are being accepted at this very moment... > > Chris > > > -----Original Message----- > > From: pgsql-hackers-owner@postgresql.org > > [mailto:pgsql-hackers-owner@postgresql.org]On Behalf Of Igor Kovalenko > > Sent: Friday, 22 March 2002 1:31 AM > > To: Luis Alberto Amigo Navarro > > Cc: bruc@acm.org; tgl@sss.pgh.pa.us; pgsql-hackers@postgresql.org > > Subject: Re: Fw: Fw: [HACKERS] bad performance on irix > > > > > > No, I've been told it is not gonna be considered for 7.2x and I shall > > wait till 7.3. > > > > Luis Alberto Amigo Navarro wrote: > > > > > > > Makes me wonder... perhaps now someone will be convinced to > > take a look > > > > at the POSIX IPC patch. On some platforms (not on Linux I am afraid) > > > > POSIX mutexes might be quite a bit faster than SYSV semaphores. > > > > > > > Is there any current patch? > > > Regards > > > > ---------------------------(end of broadcast)--------------------------- > > TIP 4: Don't 'kill -9' the postmaster > >
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Re: Fw: Fw: bad performance on irix
Bruce Momjian <pgman@candle.pha.pa.us> — 2002-03-22T18:32:32Z
Igor Kovalenko wrote: > Does that mean I should redo patch for 7.3 as is, or you guys want it to > go farther this time? The last version had compromises intended to make > changes minimal... > > Also, does anyone from Darwin or BeOS camp care? You guys should not be > working through emulation of SysV ugliness. If someone is listening, we > could come up with a version suitable for you too... Yes, we should get started. I think the idea is to have two patches, one for QNX6 and another to support Posix capabilities. The changes don't have to be minimal anymore. :-) -- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610) 853-3000 + If your life is a hard drive, | 830 Blythe Avenue + Christ can be your backup. | Drexel Hill, Pennsylvania 19026