Messages in this thread | | | Subject | loop block-mq conversion scalability issues | From | "Justin M. Forbes" <> | Date | Thu, 23 Apr 2015 16:04:10 -0500 |
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The block-mq conversion for loop in 4.0 kernels is showing us an interesting scalability problem with live CDs (ro, squashfs). It was noticed when testing the Fedora beta that the more CPUs a liveCD image was given, the slower it would boot. A 4 core qemu instance or bare metal instance took more than twice as long to boot compared to a single CPU instance. After investigating, this came directly to the block-mq conversion, reverting these 4 patches will return performance. More details are available at https://bugzilla.redhat.com/show_bug.cgi?id=1210857 I don't think that reverting the patches is the ideal solution so I am looking for other options. Since you know this code a bit better than I do I thought I would run it by you while I am looking as well.
Thanks, Justin
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