Description

This shows KLOC (thousands lines of code) changes in three kernels:

• OpenVZ 2.6.27-aivazovsky,Z based on vanilla 2.6.27 kernel.
• OpenVZ 2.6.18-028stab062.1, based on RHEL5 U3 kernel.
• RHEL5 U3 2.6.18-128.1.1.el5, based on vanilla 2.6.18 kernel.

Conclusions

• Even without drivers RHEL5 patches add/delete 434 KLOC, which is 8.5x times bigger then OpenVZ kernel modifications (51 KLOC);
• OpenVZ based on mainstream 2.6.27 kernel requires 40% less modifications (not counting modules) due to on going mainstream integration.

Source data

RHEL5 U3 2.6.18-128.1.1.el5

	       files		      add           del
	       -----		---------       -------
combined:	4962		1 190 308	210 460
 ` drivers:	2179		  800 889	166 009
 ` other:	2783		  389 419	 44 451
    ` xen	 713		  124 721	  9 087
    ` ext4	  33		   28 631	      0 /* backported */
    ` gfs	  72		   27 786	      0
    ` utrace	 114		   13 741	  6 818
    ` other	1851		  194 540	 28 546


OpenVZ 2.6.18-028stab062

combined:	 980		   79 054	  6 644
 ` mod:	  66		   34 621	      0
    ` cpt	  47		   21 747	      0
    ` other	  19		   12 874	      0
 ` core:	 914		   44 433	  6 644
    ` bc	 190		   11 719	    669
    ` fsched	  53		    4 195	    515
    ` hfixes	 222		    4 036	  1 185
    ` 4gb	  72		    2 308	    709
    ` other	 377		   22 175	  3 566


OpenVZ 2.6.27-aivazovsky

combined:	 510		   59 606	  2 921
 ` mod:	  65		   31 933	      0
 ` core:	 455		   27 673	  2 921