Re: [GHC] #5773: main = forever (putStrLn = getLine) continuously saturates a CPU when compiled
#5773: main = forever (putStrLn = getLine) continuously saturates a CPU when compiled --+- Reporter: lpsmith | Owner: Type: bug | Status: closed Priority: highest | Milestone: 7.4.1 Component: Compiler |Version: 7.4.1-rc1 Resolution: fixed| Keywords: Os: Linux| Architecture: x86_64 (amd64) Failure: Runtime performance bug | Difficulty: Unknown Testcase: | Blockedby: Blocking: |Related: --+- Changes (by igloo): * status: merge = closed * resolution: = fixed Comment: Merged as 7a5f8048fb4a9d620724a47d92762102089a6c9a. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/5773#comment:12 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #5773: main = forever (putStrLn = getLine) continuously saturates a CPU when compiled
#5773: main = forever (putStrLn = getLine) continuously saturates a CPU when compiled --+- Reporter: lpsmith | Owner: Type: bug | Status: merge Priority: highest | Milestone: 7.4.1 Component: Compiler |Version: 7.4.1-rc1 Resolution: | Keywords: Os: Linux| Architecture: x86_64 (amd64) Failure: Runtime performance bug | Difficulty: Unknown Testcase: | Blockedby: Blocking: |Related: --+- Changes (by simonmar): * status: new = merge Comment: Fix committed as d2dcac6a0291d5271bf7f8ff1394121abd6901d2 -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/5773#comment:11 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #5773: main = forever (putStrLn = getLine) continuously saturates a CPU when compiled
#5773: main = forever (putStrLn = getLine) continuously saturates a CPU when compiled --+- Reporter: lpsmith | Owner: simonmar Type: bug | Status: closed Priority: highest | Milestone: 7.4.1 Component: Compiler |Version: 7.4.1-rc1 Resolution: fixed| Keywords: Os: Linux| Architecture: x86_64 (amd64) Failure: Runtime performance bug | Difficulty: Unknown Testcase: | Blockedby: Blocking: |Related: --+- Changes (by igloo): * status: merge = closed * resolution: = fixed Comment: Merged as e3b7e3352c6bba0bf7b6991e5485264a868e4800 -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/5773#comment:9 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #5773: main = forever (putStrLn = getLine) continuously saturates a CPU when compiled
#5773: main = forever (putStrLn = getLine) continuously saturates a CPU when
compiled
---+
Reporter: lpsmith | Owner: simonmar
Type: bug | Status: new
Priority: highest | Milestone: 7.4.1
Component: Compiler| Version: 7.4.1-rc1
Keywords: | Os: Linux
Architecture: x86_64 (amd64) | Failure: Runtime performance bug
Difficulty: Unknown |Testcase:
Blockedby: |Blocking:
Related: |
---+
Comment(by marlowsd@…):
commit fac8ecbbafde17dd92439c41747223c43e9d2b80
{{{
Author: Simon Marlow marlo...@gmail.com
Date: Mon Jan 16 09:49:24 2012 +
Fix bug causing polling instead of blocking in the non-threaded RTS
(#5773)
This was a regression introduced accidentally in
6b1098511aaabd2c9503ee7be6da1944466f9cb4. We were previously passing
a large time value to select() to simulate blocking, and this broke
due to a change from unsigned to signed arithmetic. I've refactored
it to be less fragile now - we just pass NULL as the timeval parameter
to select(), which is the correct way to do blocking.
rts/posix/Select.c | 35 +--
1 files changed, 17 insertions(+), 18 deletions(-)
}}}
--
Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/5773#comment:7
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Re: [GHC] #5773: main = forever (putStrLn = getLine) continuously saturates a CPU when compiled
#5773: main = forever (putStrLn = getLine) continuously saturates a CPU when compiled ---+ Reporter: lpsmith | Owner: simonmar Type: bug | Status: merge Priority: highest | Milestone: 7.4.1 Component: Compiler| Version: 7.4.1-rc1 Keywords: | Os: Linux Architecture: x86_64 (amd64) | Failure: Runtime performance bug Difficulty: Unknown |Testcase: Blockedby: |Blocking: Related: | ---+ Changes (by simonmar): * status: new = merge Comment: Thanks for the report - a good one to find before the release. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/5773#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #5773: main = forever (putStrLn = getLine) continuously saturates a CPU when compiled
#5773: main = forever (putStrLn = getLine) continuously saturates a CPU when
compiled
---+
Reporter: lpsmith | Owner: simonmar
Type: bug | Status: new
Priority: highest | Milestone: 7.4.1
Component: Compiler| Version: 7.4.1-rc1
Keywords: | Os: Linux
Architecture: x86_64 (amd64) | Failure: Runtime performance bug
Difficulty: Unknown |Testcase:
Blockedby: |Blocking:
Related: |
---+
Changes (by igloo):
* owner: = simonmar
* difficulty: = Unknown
* priority: normal = highest
* milestone: = 7.4.1
Comment:
Thanks for the report.
This is a regression: It works in 7.2 and 7.0.
Simon, do you know what's up?
I skimmed 6b1098511aaabd2c9503ee7be6da1944466f9cb4, and while I don't
think it's relevant, shouldn't the tv_nsec and tv_usec fields in these
hunks have the complete seconds removed?:
{{{
-it.it_value.tv_sec = itimer_interval / 1000;
-it.it_value.tv_nsec = (itimer_interval % 1000) * 100;
+it.it_value.tv_sec = TimeToSeconds(itimer_interval);
+it.it_value.tv_nsec = TimeToNS(itimer_interval);
}}}
{{{
-it.it_value.tv_sec = itimer_interval / 1000;
-it.it_value.tv_usec = (itimer_interval % 1000) * 1000;
+it.it_value.tv_sec = TimeToSeconds(itimer_interval);
+it.it_value.tv_usec = TimeToUS(itimer_interval);
}}}
--
Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/5773#comment:3
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Re: [GHC] #5773: main = forever (putStrLn = getLine) continuously saturates a CPU when compiled
#5773: main = forever (putStrLn = getLine) continuously saturates a CPU when
compiled
---+
Reporter: lpsmith | Owner: simonmar
Type: bug | Status: new
Priority: highest | Milestone: 7.4.1
Component: Compiler| Version: 7.4.1-rc1
Keywords: | Os: Linux
Architecture: x86_64 (amd64) | Failure: Runtime performance bug
Difficulty: Unknown |Testcase:
Blockedby: |Blocking:
Related: |
---+
Comment(by lpsmith):
Ok, I was mistaken. The program I though I compiled with ghc-7.4.1-rc1 I
actually compiled with ghc-7.0.3, and so the program I used to test
{{{threadWaitRead}}} also saturates the CPU. Although it may not be of
any great interest to the bug-hunters, I'll attach the program, it's a
straightforward port of a sample program from the PostgreSQL source
distribution to the http://hackage.haskell.org/package/postgresql-libpq
bindings.
So it seems to be a problem with blocking IO in general. I find it
curious that none of my test programs exhibit this problem when run inside
GHCi.
--
Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/5773#comment:4
GHC http://www.haskell.org/ghc/
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Re: [GHC] #5773: main = forever (putStrLn = getLine) continuously saturates a CPU when compiled
#5773: main = forever (putStrLn = getLine) continuously saturates a CPU when compiled ---+ Reporter: lpsmith | Owner: simonmar Type: bug | Status: new Priority: highest | Milestone: 7.4.1 Component: Compiler| Version: 7.4.1-rc1 Keywords: | Os: Linux Architecture: x86_64 (amd64) | Failure: Runtime performance bug Difficulty: Unknown |Testcase: Blockedby: |Blocking: Related: | ---+ Comment(by igloo): GHCi is linked with `-threaded` by default, which uses a different implementation of this stuff. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/5773#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #5773: main = forever (putStrLn = getLine) continuously saturates a CPU when compiled
#5773: main = forever (putStrLn = getLine) continuously saturates a CPU when compiled ---+ Reporter: lpsmith | Owner: simonmar Type: bug | Status: new Priority: highest | Milestone: 7.4.1 Component: Compiler| Version: 7.4.1-rc1 Keywords: | Os: Linux Architecture: x86_64 (amd64) | Failure: Runtime performance bug Difficulty: Unknown |Testcase: Blockedby: |Blocking: Related: | ---+ Comment(by lpsmith): Oh, right, I didn't notice that the program I was writing when I ran into this bug wasn't not being linked -threaded. And this problem does go away when I do that. Thanks! -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/5773#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #5773: main = forever (putStrLn = getLine) continuously saturates a CPU when compiled
#5773: main = forever (putStrLn = getLine) continuously saturates a CPU when
compiled
-+--
Reporter: lpsmith | Owner:
Type: bug | Status: new
Priority: normal | Component: Compiler
Version: 7.4.1-rc1| Keywords:
Os: Linux| Architecture: x86_64 (amd64)
Failure: Runtime performance bug | Testcase:
Blockedby: | Blocking:
Related: |
-+--
Comment(by lpsmith):
The problem appears to be in {{{getLine}}}; you can remove {{{forever}}}
and still consume 100% of a CPU (until you type something in and the
program exits of course.)
--
Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/5773#comment:1
GHC http://www.haskell.org/ghc/
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[GHC] #5773: main = forever (putStrLn = getLine) continuously saturates a CPU when compiled
#5773: main = forever (putStrLn = getLine) continuously saturates a CPU when
compiled
-+--
Reporter: lpsmith | Owner:
Type: bug | Status: new
Priority: normal | Component: Compiler
Version: 7.4.1-rc1| Keywords:
Os: Linux| Architecture: x86_64 (amd64)
Failure: Runtime performance bug | Testcase:
Blockedby: | Blocking:
Related: |
-+--
{{{
$ ghc --make copycat.hs
$ ./copycat
}}}
--
Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/5773
GHC http://www.haskell.org/ghc/
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