Messages in this thread |  | | | Date | Wed, 17 Jan 2001 03:17:27 -0800 (PST) | | From | Rob Landley <> | | Subject | Re: qlogicfc.c hard lockups in 2.4.0 |
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More data:
I changed QLOGICFC_REQ_QUEUE_LEN from 127 to 255, and the lockup hasn't happened again yet, in circumstances that fairly reliably reproduced it before. (Could just mean I have to hit it harder.)
BUT: I am still getting those "no handle slots, this should not happen" messages. (Especially when I play with nicing my dd down to -20, although that may be cheating...) These seem to match with noticeable stalls in the drive array light blinkiness, where about every 2 seconds there's a visible pause in the whole array. If I do a read that's short enough to NOT cause one of these stalls, I get 178 megabytes/second throughput (which is about up towards the theoretical limit of the two qlogic fiber channel cards and the ten drives per card).
With the stalls, it gets dragged down into the 150 megabyte per second range. That's right on the border of causing dropped capturing from the hdtv card, and stalls playing to it. (I forget exactly what I need, something like 157 megabytes/second... Bigger is better, of course...)
According to top, at least one CPU is pegged during all this, by the way. dd uses 99.9% of available cpu time, with bdflush taking another 32% or so (on the other cpu, one assumes. :) Guess: lots of copying of the zero page to fill up dd's buffers? I'm trying to do an i/o bound test, may have to write my own it seems. Oh well, no biggie... (The real applicatino for this is dma into and out of a mondo ring buffer, not particularly cpu intensive at all, you'd think...)
Fun fun fun... Sun's coming up in an hour, I should probably get some sleep.
Rob
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