Monthly Archives: February 2013

关于ext4 tree的说明

周五给ext4发了一个patch但是Ted说无法apply

This patch didn’t apply since it was apparently against an older
version of the extents status patches. Here is the version after I
fixed it up so it would apply into the current ext4 tree.

因为我是在Linus tree上生成的patch,我就问了下倾向于使用哪个tree,没想到Ted给了一个非常详细的解释,对了解ext4开发/维护工作还挺有帮助的,摘录在此

The ext4 tree in general is the one which is preferred; the dev branch
is the tip of what we hope to push to Linus. At the moment, it’s in
final testing. The three branch pointers which are important on the
ext4 tree are origin, master, and dev. The origin branch is where we
have branched off of Linus’s tree. At the moment, ext4/origin is
pointing at v3.8-rc3. The ext4/master branch is always between origin
and dev (inclusive). The dev branch is a rewinding branch, which
means that everything between master and dev may be get modified
(i.e., to add a Reviewed-by: or to fix up some comments, etc.), or may
get dropped (if it turns out we discover the patch is not ready for
prime time). The dev branch is also what gets included into
linux-next.

The master branch represents those patches which have been
“finalized”, which means once we bump the master branch, all of the
commits between origin and master (inclusive) are guaranteed not to
change. So for people who are building on top of master, it’s safe
for them to use git. For people who are building on top of dev, if
you want to make changes, it’s recommended you use a tool like quilt,
guilt, or stgit.

Speaking of quilt/guilt, the set of patches between master and dev can
be found here:

http://repo.or.cz/w/ext4-patch-queue.git
git://repo.or.cz/ext4-patch-queue.git

For those people who are interested, or who want to more easily cherry
pick specific patches out of the ext4 patch queue, the ext4/dev branch
(usually, assuming I’ve remembered to update the ext4 patch queue
tree) can be reconstructed as follows:

git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git ext4
mkdir -p ext4/.git/patches
cd ext4/.git/patches
git clone git://repo.or.cz/ext4-patch-queue.git dev
cd dev
sh timestamps
cd ../../..
git branch dev $(head -1 .git/patches/dev/series | sed -e ‘s/# BASE //’)
git checkout dev
guilt push stable-boundary
guilt pop

(This assumes you are using guilt version v0.35, found at
git://repo.or.cz/guilt.git; note that the tip of the guilt tree has
incompatible changes in how they parse patches, so I haven’t upgraded
to the tip of guilt tree yet.)

Anyway, most people will send me patches against Linus’s tree, and
that’s fine; if there are problems, I can usually fix up the patches.
But it’s most convenient for me if people send against either the
ext4/master, or most preferably, the ext4/dev branch.

BTW, I’ve updated the ext4 wiki to include the above information.

Thanks,

– Ted

总结一下就是:

1. ext4 tree有三个branch,origin master dev
a) origin是从Linus tree分出来的点
b) master是稳定了的commit,打算下一次push给Linus的
c) dev是还不稳定/在测试的commit,可能会修改
d) 可以理解为 origin是起点,dev是终点,master用作一个标尺,origin-master之间是的commit是稳定的,可以提交给Linus的,master-dev之间是还在开发/测试的commit,一旦稳定了就更新master,把新commit包含进去
2. 很多人在Linus tree上生成patch,这没问题,Ted如果遇到不能apply的情况他会修复
3. 使用master或者dev分支更对Ted来说更方便,他更倾向于dev分支
4. 用dev分支的话Ted推荐使用guilt/quilt等工具,用master分支用git就行

git还没那么熟悉,还不会灵活使用各种分支和patch管理工具,前路漫漫啊。

总参大院羽毛球活动 2013-02-23

虽然周五打篮球很累了,到周六腿还是酸的,但还是禁不住羽毛球的诱惑。年前手痒在天羽上寻觅的活动又报名参加了一次。不过事实证明勉强打球是没啥好下场的。

这次吸取上次经验,去之前先吃了点东西,然后去公司拿装备,不到6点到了小西天的总参大院。早到了15分钟,先看看别人打球。一个12 3岁的小男孩打的很不错,动作、发力都跟大人差不多了,估计和他单打的话都不敢保证能赢。由于是年后刚回来吧,人少,打了很多局,但印象中只赢了一局,委屈跟我配合打双的朋友了。我这次最主要的特点就是失误多,各种出界下网判断失误。稳定性还是太差了,这可能需要有人给我多球帮忙训练了。另外双打还是不会配合,很多勉强接球,其实都可以交给队友的。看来很有必要学习一下双打的基本知识,比如站位、跑动等基本的。

其实说到失误多,不够稳定,还是基础不够扎实,欠练,继续努力吧。

自己寻觅球局

周六,难得的好空气,却只能宅在家里,没有活动没有饭局没有球局。周五晚上看了些羽毛球视频,看的手痒痒。下午的时候实在忍不住了,既然没人捡,那就自力更生自己找球局吧。
先在水木羽毛球版翻了翻,北苑附近有一个新开球馆免费试打,有人组织去打了,不过我报名晚了,已经报满。后来上了天天羽毛球看看有没有今天活动的俱乐部,找到一个小西天总参院里的活动,那边还算熟悉,而且还能报名,果断报名了。然后就是去公司拿装备,去小西天。
北京师范大学站下车之后南走一点就是,在路西。但进到总参之后体育馆不是很好找,幸好在路上遇到了一个背着球包的人,遂搭讪,得知也是去打球就一起走了,感觉七拐八拐才到。球馆不大,四块场地,塑胶地面,棚顶很高,只是灯光在棚顶,抬头容易晃眼。两块场地一共11个人,3个年纪稍微大一些的,包括我6个算年轻的,2个女生。
整场都是双打。第一局跟带我来的人一队,对手是一个年轻的和一个年长的。队友水平不错,我还是失误连连,对手年轻的没怎么认真打(从看他之后的比赛看出来的),年长的后场球基本都回不到位,比较轻松的拿下了一句。亮点是我两次发球都很贴线,对方误以为违例没接,结果进线得分。第二局跟一个女生搭档,显然这个女生是弱点,发球半高,还好对方没有扑球,移动慢没后场,一场下来非常累,基本在两个底角来回奔波了。输球在所难免,只是比分没那么难看,ms是15:21.后来两局都是跟年长的搭档,两个人失误都很多,两局都输了。中间还有两局,没什么印象了,好像是一赢一输。最后一局是跟组织者搭档,打两个年长者。对方明显运动能力下降,回球下网,网前球接不到,后场球不到位,我们一度11:0领先。后来我有所松懈,连续失误,不过最后还是赢了。
最后要走之前跟另外一个大姐搭档,打整场最厉害的一个和一个稍年长的。大姐网前封网和接杀都很不错,只是没有后场,我又是在后场来回奔波,加上对方后场压的很到位,我就更累了。其中一个球我和大姐连续接杀,四五个回合之后以我回球失误下网告终。最后没打完,场地时间到,下一场的人来了。
这次打球的感觉,首先失误太多,其次后场球容易出界。失误表现在对双打的端线宽度不适应,经常放过好球,回球经常出端线,扑球杀球下网也有一些。在回后场球的时候经常出界,可能是球比较走的原因吧。亮点也是有一些的,第一局有一个还不错的网前搓球,接发球勾两个网角对手都没接到,场上移动还算积极,有几个杀球还可以吧。
以后找不到人打球了就去俱乐部玩玩也还好,现在水平没有以前那么菜了,一般的还可以上去打打,就是双打经验太少了。