Messages in this thread | | | Date | Wed, 30 Jan 2008 17:50:52 +0100 | From | "Bart Van Assche" <> | Subject | Re: Integration of SCST in the mainstream Linux kernel |
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On Jan 30, 2008 5:34 PM, James Bottomley <James.Bottomley@hansenpartnership.com> wrote: > > On Wed, 2008-01-30 at 09:38 +0100, Bart Van Assche wrote: > > On Jan 30, 2008 12:32 AM, FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> wrote: > > > > > > iSER has parameters to limit the maximum size of RDMA (it needs to > > > repeat RDMA with a poor configuration)? > > > > Please specify which parameters you are referring to. As you know I > > had already repeated my tests with ridiculously high values for the > > following iSER parameters: FirstBurstLength, MaxBurstLength and > > MaxRecvDataSegmentLength (16 MB, which is more than the 1 MB block > > size specified to dd). > > the 1Mb block size is a bit of a red herring. Unless you've > specifically increased the max_sector_size and are using an sg_chain > converted driver, on x86 the maximum possible transfer accumulation is > 0.5MB.
I did not publish the results, but I have also done tests with other block sizes. The other sizes I tested were between 0.1MB and 10MB. The performance difference for these other sizes compared to a block size of 1MB was small (smaller than the variance between individual tests results).
Bart.
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