On Fri, Aug 3, 2012 at 8:10 AM, Jef Driesen jefdriesen@telenet.be wrote:
On 2012-08-03 01:46, Artur Wroblewski wrote:
I am using libdivecomputer 781f0db71f7a06591e819f7960dd5b504b4f16a0 at the moment and when trying to download the data from my Sensus Ultra I can see the following on Linux via strace
select(4, [3], [], [], {5, 0}) = 1 (in [3], left {4, 999992}) read(3, "\1\0\323u\245", 31095) = 5 select(4, [3], [], [], {5, 0}) = 1 (in [3], left {4, 2265}) read(3, "\2\3d\35\321\202\n\7\2\0z\203\177", 31090) = 13 select(4, [3], [], [], {5, 0}) = 1 (in [3], left {4, 999869}) read(3, "\1\371\0\n\0W\4", 31077) = 7 select(4, [3], [], [], {5, 0}) = 1 (in [3], left {4, 999995}) read(3, "\17\0\1", 31070) = 3 select(4, [3], [], [], {5, 0}) = 1 (in [3], left {4, 999968}) read(3, "\0`@", 31067) = 3
The behavior you see with strace is perfectly normal.
[...]
The select/read calls are normal of course, but the amount of bytes read I consider as weird - seems like device is providing the data in quite slow manner or the read call stops reading too fast.
The data download is very slow (still downloading actually ;) and I wonder what that could be
- some change in libdivecomputer (it reads 1-5 bytes at once :/)
- the device dies
- Linux kernel 3.5.0
- combination of all above
Does anyone experience something similar?
Have you measured the download time?When I check an older logfile of mine (version c4172ecdf6c2f6b68eba7e06e446d46aef66a729), a full download (2080768 bytes) took 206 seconds on my system. In a more recent logfile I have lying around (downloaded on 2012/06/28, don't know the exact version, but probably 87397a4ea1c63d78efd9bf751dee19f54257a6f9), it took only 186 seconds. So that's perfectly in line with the expected timings. Do you get very different numbers?
It took about 1h! In the past I was getting about 3 minutes.
I tried various versions of libdivecomputer as well (the above, 0.1.0 and a217a0fb803bbb6ada1d298cd534ed2bb092b25b) and older kernel 3.3.0.
I am downloading all dives, but getting none of them. My previous data dump contains 199 dives. :) This one shall have around 215. I have not seen significant time degradation in the past.
Well, looks like device issue, I will take it diving and let's see if there will be some improvement afterwards. ;)
Thanks for all the detailed explanation.
Best regards,
w