I read that with the 4.15 Kernel with build-in patches for the hypothetical problem comes with 15-30% performance loss.
That's way overblown, because the performance loss happens during the switch between userspace and kernelspace. Sensible programs don't spend most of their time doing thousands of tiny system calls.
A 30% reduction in performance there is bad, but not the same as a 30% slower computer.
Apologies for this newbie question. We have inherited an IBM p5 520 (9111-520) running AIX 6.1.0.0 which seems to be the base install and no further patches installed.
Is this vulnerable to the Spectre/Meltdown threat?
Are patches available?
Looks like AIX 6.1.0.0 went 'end of support' in... (8 Replies)
This seems a bit serious:
Meltdown, Spectre: The password theft bugs at the heart of Intel CPUs • The Register
Vulnerability Note VU#584653 - CPU hardware vulnerable to side-channel attacks
Project Zero: Reading privileged memory with a side-channel (8 Replies)
This link is to a page that has two short videos that feature Linus Torvalds discussing the Linux kernel. After you watch the first video, scroll down some more to reach the second video. (0 Replies)
I had an issue with a second hard disk in my machine. I have a sparc station running solaris 7. It was working fine but now it wont mount on boot up and when you try to mount it manually it gives an I/O error. I tried a different disk as a control which was fine. What I want to know is if my... (3 Replies)
Hello people,
Im just about to install linux and unix but would like to know what the best Partition type format is for both of them.
Can anyone tell me
Thankyou in advanced (1 Reply)
GIT-MERGE-BASE(1) Git Manual GIT-MERGE-BASE(1)NAME
git-merge-base - Find as good common ancestors as possible for a merge
SYNOPSIS
git merge-base [-a|--all] <commit> <commit>...
DESCRIPTION
git merge-base finds best common ancestor(s) between two commits to use in a three-way merge. One common ancestor is better than another
common ancestor if the latter is an ancestor of the former. A common ancestor that does not have any better common ancestor is a best
common ancestor, i.e. a merge base. Note that there can be more than one merge base for a pair of commits.
Among the two commits to compute the merge base from, one is specified by the first commit argument on the command line; the other commit
is a (possibly hypothetical) commit that is a merge across all the remaining commits on the command line. As the most common special case,
specifying only two commits on the command line means computing the merge base between the given two commits.
As a consequence, the merge base is not necessarily contained in each of the commit arguments if more than two commits are specified. This
is different from git-show-branch(1) when used with the --merge-base option.
OPTIONS -a, --all
Output all merge bases for the commits, instead of just one.
DISCUSSION
Given two commits A and B, git merge-base A B will output a commit which is reachable from both A and B through the parent relationship.
For example, with this topology:
o---o---o---B
/
---o---1---o---o---o---A
the merge base between A and B is 1.
Given three commits A, B and C, git merge-base A B C will compute the merge base between A and a hypothetical commit M, which is a merge
between B and C. For example, with this topology:
o---o---o---o---C
/
/ o---o---o---B
/ /
---2---1---o---o---o---A
the result of git merge-base A B C is 1. This is because the equivalent topology with a merge commit M between B and C is:
o---o---o---o---o
/
/ o---o---o---o---M
/ /
---2---1---o---o---o---A
and the result of git merge-base A M is 1. Commit 2 is also a common ancestor between A and M, but 1 is a better common ancestor, because 2
is an ancestor of 1. Hence, 2 is not a merge base.
When the history involves criss-cross merges, there can be more than one best common ancestor for two commits. For example, with this
topology:
---1---o---A
/
X
/
---2---o---o---B
both 1 and 2 are merge-bases of A and B. Neither one is better than the other (both are best merge bases). When the --all option is not
given, it is unspecified which best one is output.
AUTHOR
Written by Linus Torvalds <torvalds@osdl.org[1]>
DOCUMENTATION
Documentation by David Greaves, Junio C Hamano and the git-list <git@vger.kernel.org[2]>.
GIT
Part of the git(1) suite
NOTES
1. torvalds@osdl.org
mailto:torvalds@osdl.org
2. git@vger.kernel.org
mailto:git@vger.kernel.org
Git 1.7.1 07/05/2010 GIT-MERGE-BASE(1)