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Re^9: Threaded Code Not Faster Than Non-Threaded -- Why?

by BrowserUk (Pope)
on Jan 06, 2014 at 07:06 UTC ( #1069465=note: print w/replies, xml ) Need Help??


in reply to Re^8: Threaded Code Not Faster Than Non-Threaded -- Why?
in thread Threaded Code Not Faster Than Non-Threaded -- Why?

I'd suggest trying the following modification:

my $thread_term :shared = 0; my $threads_init :shared = 0; my $file_read_sem : shared; + ### Add this ... WORKER: while ( !$thread_term && defined ( my $file = $work_queue-> +dequeue ) ) { { + ### Add this lock $file_read_sem; + ### Add this open my $fh, '<', $file or do { lock $d_counter; $d_counter++ +; next WORKER }; my $data = <$fh>; close $fh; } + ### Add this

With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.

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Re^10: Threaded Code Not Faster Than Non-Threaded -- Why?
by Tommy (Chaplain) on Jan 06, 2014 at 18:27 UTC
    I'd suggest trying the following modification

    ...To prevent disk thrashing?

    Tommy
    A mistake can be valuable or costly, depending on how faithfully you pursue correction
      To prevent disk thrashing?

      Yes. But you'll need to try it; and the effects will probably vary for different file systems.

      For lots of small files it might speed things up; for lots of big ones it might slow things down. For a mix; you'll need to measure.


      With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
      Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
      "Science is about questioning the status quo. Questioning authority".
      In the absence of evidence, opinion is indistinguishable from prejudice.

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