[OpenWrt-Devel] Toolchain issue: Significant decrease in performance of binaries produced by Barrier Breaker relative to Attitude Adjustment

[Hauke Mehrtens]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On 08/30/2014 06:45 PM, Matthias Schiffer wrote:
> On 08/30/2014 06:42 PM, Matthias Schiffer wrote:
>> Hi, I've noticed that the code produced by Barrier Breaker's
>> toolchain sometimes has significantly worse performance that that
>> built by Attitude Adjustment.
>> 
>> I can see this extremely with the VPN tool "fastd" developed and 
>> maintained by me: On the same Barrier Breaker system, a binary
>> built by the default Barrier Breaker toolchain (GCC 4.8-linaro)
>> gets about 35% less throughput than one built with Attitude
>> Adjustment (GCC 4.6-linaro). With the 4.6-linaro toolchain of
>> Barrier Breaker, I still get 20% worse performance than with the
>> 4.6-linaro of Attitude Adjustment.
>> 
>> Do you have any suggestions what I can do to solve or analyze the
>> issue? Any compiler flags I should try fiddling with? Optimizing
>> with -Os vs. -O3 doesn't seem to make a difference.
>> 
>> Thanks, Matthias
>> 
> 
> I forgot to tell that this is on ar71xx.

This could be a problem caused by mips16. We use that in BB to create
smaller binaries. but Jonas saw a performance problem in some
applications, mostly stuff doing crypto (big integer calculations).

Can you try to build the BB toolchain without the mips16 feature in
target/linux/ar71xx/Makefile and try your application again.

Hauke

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1
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=e4/e
-----END PGP SIGNATURE-----
_______________________________________________
openwrt-devel mailing list
openwrt-devel at lists.openwrt.org
https://lists.openwrt.org/cgi-bin/mailman/listinfo/openwrt-devel