PT下载的时候，CPU负载怎么这么高啊，达到5.x了，看片都卡

zy_spring

用的是自带的transmission版本，12M ADSL，可以满速
2700DC的主板，2核4线程，2.13G的主频，4G RAM，3x2T raid5，硬件应该不是问题吧
但是当PT下载满速的时候，CPU的负载过高，达到5.x了，GUI和SSH用top命令都看了，是一样的
这样导致的结果是PT下载的时候，samba速度太慢了，连看片都卡。
请帮忙看看吧。

jone

看一下top，哪个值占用高。

zy_spring

top看了啊，是transmission，不过最高也才8%，load average和CPU的使用率好像关系不大的，load average到了5.6了，可是CPU使用率没有超过10%。
看了一下transmission的trac，好像有这么一个bug，不过我的transmission已经是2.20版本了，看来需要升级了

Last modified 17 months ago

by default, disable prefetch for lightweight builds



Reported by:

jusid

Owned by:

jordan



Priority:

Normal

Milestone:

2.20



Component:

Transmission

Version:

2.13



Severity:

Major

Keywords:

patch



Cc:









Description


Since Transmission 2.0, I noticed that it produces heavy load for my NMT device when seeding. Even several connected peers cause Load average to be 3-4. On the same time, Transmission 1.75 does not have such problem and the load average in the same scenario is about 1.

I started digging and found that transmission 2.x produces excessive disk activity, compared to pre 2.0 versions. On further investigation, I found that the prefetching, introduced in v2.0 is guilty for this. I disabled the prefetching and built the transmission for my NMT. Voila - system load dropped to <1 instead of 3-4. The explanation is simple, my NMT have small amount of RAM and system have very small disk cache for that reason. Prefetched data do not remain in disk cache and disk reads just wasted.

Attached patch fixes this problem by disabling prefetch if TR_LIGHTWEIGHT is defined. Transmission builds with --enable-lightweight will have prefetching disabled. Please apply this patch before final 2.20 release.

asher

看不懂呀，看来玩NAS还是个技术活。

jiazhou

看片子而已做raid5做啥

nt88488

做raid5做啥