Re: [RFC] 1 pass architecture and sorted writing.

[Hideki IWAMOTO]

Hi.

On Thu, 13 May 2010 18:44:12 +0900, Shigio YAMAGUCHI wrote...
> (2) Sorted writing
>       The (1) brings big GRTAGS and decrease at the writing speed.
>       To avoid it, the records written to the tag files are sorted beforehand.
>       This function becomes effective if DBOP_SORTED_WRITE flag is specified
>       for function dbop_open(). It uses external POSIX sort command.

When C lolale is not used, the performance might be worse than CVS version. 
You should restore
  set_env("LC_ALL", "C");
deleted in gtags.c revision 1.183. 
http://cvs.savannah.gnu.org/viewvc/global/gtags/gtags.c?root=global&r1=1.182&r2=1.183


The elapsed time measured on Fedora core 4 is as follows.  
CPU: Pentium D (dual core)
Input: linux-2.6.33 source
-------------- -------------- --------------------------------
                                     patched version
 B-tree cache   CVS version   ---------------- ---------------
                              LANG=ja_JP.UTF-8     LANG=C
-------------- -------------- ---------------- ---------------
     32MiB       107.09 sec      76.25 sec        45.27 sec
     64MiB        70.25 sec      78.61 sec        44.65 sec
    128MiB        68.02 sec      79.64 sec        45.61 sec
-------------- -------------- ---------------- ---------------


==== CVS version ====
$ foreach cachesize ( 33554432 67108864 134217728 )
foreach? rm -fr linux-2.6.33; tar xfj ~/download/linux/linux-2.6.33.tar.bz2; 
sync
foreach? (cd linux-2.6.33; time env GTAGSCACHE=$cachesize gtags)
foreach? end
47.422u 6.380s 1:47.09 50.2%    0+0k 0+0io 2pf+0w
47.858u 4.424s 1:10.25 74.4%    0+0k 0+0io 2pf+0w
48.131u 3.660s 1:08.02 76.1%    0+0k 0+0io 2pf+0w

==== patched version ====
$ foreach locale ( ja_JP.UTF-8 C )
foreach? foreach cachesize ( 33554432 67108864 134217728 )
foreach? rm -fr linux-2.6.33; tar xfj ~/download/linux/linux-2.6.33.tar.bz2; 
sync
foreach? (cd linux-2.6.33; time env LANG=$locale GTAGSCACHE=$cachesize gtags)
foreach? end
foreach? end
76.860u 4.736s 1:16.25 107.0%   0+0k 0+0io 5pf+0w
79.456u 4.524s 1:18.61 106.8%   0+0k 0+0io 0pf+0w
79.912u 4.360s 1:19.64 105.8%   0+0k 0+0io 2pf+0w
39.106u 4.232s 0:45.27 95.7%    0+0k 0+0io 2pf+0w
38.946u 4.620s 0:44.65 97.5%    0+0k 0+0io 2pf+0w
39.074u 4.592s 0:45.61 95.7%    0+0k 0+0io 3pf+0w

----
Hideki IWAMOTO  address@hidden