From: Mikulas Patocka <mpatocka@xxxxxxxxxx> Date: Thu, 24 Jul 2008 17:49:14 -0400 (EDT) > * it is prone to bugs and hard to maintain, because the same value must be > calculated in blk-merge.c and in architectural iommu functions --- if the > value differs, you create too long request, corrupt kernel memory and > crash (happened on sparc64). Anyone changing blk-merge in the future will > risk breaking something on the architectures that use BIO_VMERGE_BOUNDARY > --- and because these architectures are so rare, the bug will go unnoticed > for long time --- like in the case of sparc64. I completely agree with this point. This VMERGE stuff is now a non-trivial maintainence burdon because anyone who wants to hack on the block layer has to be mindful of VMERGE but is very unlikely to have access to a system that it can even be tested on. And the answer isn't "James Bottomly will test your changes for you", because that simply doesn't scale. I still say we should definitely remove the VMERGE code. It's not worth the maintainence hassle just for some SG chaining test rig on some obscure platform. I really only hear one person who really wants this code around any more. Is that the Linux way? :-) Can't he patch it into his tree when he needs it or write an alternative way to stress the SG chaining code? He has the source, right? :-))) -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
