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Full Discussion: piping problem with xargs
Top Forums Shell Programming and Scripting piping problem with xargs Post 302545746 by tange on Tuesday 9th of August 2011 11:05:35 AM
Old 08-09-2011
GNU Parallel makes it often easy to generate command lines:
Code:
parallel "echo {}; cut -f5 {} | sort -k1.3n | uniq | wc -l" ::: *.rod

It will also run the jobs in parallel. If you jobs are multithreaded and you see 100% utilization of your cores all the time then you will not see a speed up using GNU Parallel.

If, however, your jobs have I/O and therefore sometimes wait for data, then it might be faster to have more processes running, that can utilize the CPU when other processes are waiting.

GNU Parallel can be made to look at the load average and not start more jobs if the load average is above a certain limit. Default (-j+0) is to start 1 job per CPU core regardless of load average.

If you want multiple instances of GNU Parallel to communicate, and not have more than N jobs in total - no matter how many times you start parallel, you should look at 'sem': http://www.gnu.org/software/parallel/sem.html
This User Gave Thanks to tange For This Post:
ivpz
 

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LEARN ABOUT MOJAVE

git-pack-redundant

GIT-PACK-REDUNDANT(1)                                               Git Manual                                               GIT-PACK-REDUNDANT(1)

NAME

       git-pack-redundant - Find redundant pack files

SYNOPSIS

       git pack-redundant [ --verbose ] [ --alt-odb ] < --all | .pack filename ... >

DESCRIPTION

       This program computes which packs in your repository are redundant. The output is suitable for piping to xargs rm if you are in the root of
       the repository.

       git pack-redundant accepts a list of objects on standard input. Any objects given will be ignored when checking which packs are required.
       This makes the following command useful when wanting to remove packs which contain unreachable objects.

       git fsck --full --unreachable | cut -d ' ' -f3 |  git pack-redundant --all | xargs rm

OPTIONS

       --all
           Processes all packs. Any filenames on the command line are ignored.

       --alt-odb
           Don't require objects present in packs from alternate object directories to be present in local packs.

       --verbose
           Outputs some statistics to stderr. Has a small performance penalty.

SEE ALSO

       git-pack-objects(1) git-repack(1) git-prune-packed(1)

GIT

       Part of the git(1) suite

Git 2.17.1                                                          10/05/2018                                               GIT-PACK-REDUNDANT(1)
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