Messages in this thread | | | Date | Wed, 12 Nov 1997 15:19:39 -0500 | From | Bill Hawes <> | Subject | Re: Another Linux performance anomaly with 1+ GB files |
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Scott Laird wrote:
> The only time I've seen the slowdowns, they've occurred during a read > from the 4k filesystem. I'm not sure if the WCHAN reported by ps is > accurate or not, but it was reporting 1261d9, which is in the middle > of try_to_free_buffers, according to my System.map.
There aren't supposed to be any blocking operations in try_to_free_buffer. Could the task perhaps be stuck in a tight loop repeatedly calling try_to_free_buffer()? The next time it gets stuck, try hitting alt-scroll-lock a few times to get the current address, and then look this up your System.map. If the address is changing but usually in try_to_free_buffer(), the system is probably looking for memory and repeatedly trying to free buffers.
Regards, Bill
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