Hi,
2024年8月20日 21:36，Greg Kroah-Hartman gregkh@linuxfoundation.org 写道：
On Tue, Aug 20, 2024 at 09:19:04PM +0800, Miao Wang wrote:
Hi, Greg
I saw you have included commit 7697a0fe0154 ("LoongArch: Define __ARCH_WANT_NEW_STAT in unistd.h") in your stable trees, which actually introduced new sys calls newfstatat and fstat to Loongarch.
See the documentation in that commit for why it was done.
Thanks for your explanation. I totally understand the necessity of re-introducing thees two syscalls. I just wonder whether there is any limitation on what can be included in to the stable trees. If there was no limitation, theoretically, I could also maintain a so-called stable tree by applying all the patches from torvalds' tree, except those that bumps the version number. Apparently such a "stable" tree is far from stable.
I wonder if it is correct to add new syscalls, which actually changes the kernel features, in stable releases, as it might confuse downstream developers because they may assume the existence of a certain feature after a certain version.
Version numbers should never be used to be checked for anything as they are only a "moment in time" stamp. They do not reflect features or capabilities or anything else.
I agree with you and Cyril on the version numbers, recalling that kernels on RHEL numbered on 3.10 contains various new features.
Test for functionality if you want to check for something, that's the only way it will ever work on all of the variants of different "enterprise" kernels.
Thanks again for your quick reply.
thanks,
greg k-h