Re: Warning - running *really* short on DMA buffers while doingfiletransfers

Andrew Morton
2002-09-27T19:53:33Z

Andrew Morton wrote:
>
> ...
> One sample trace is at
> http://www.zip.com.au/~akpm/linux/patches/trace.txt
>

Another thing to note from that trace is that many writes
went through the entire submit_bio/elv_next_request/bio_endio
cycle between the submission and completion of the read.

So there was:

submit_bio(the read)
elv_next_request(the read)
...
submit_bio(a write)
elv_next_request(that write)
bio_endio(that write)
...
bio_endio(the read)

For many writes. I'm fairly (but not 100%) sure that the same
behaviour was seen with four tags.