40% slowdown with dynamic /bin/sh

[Jonathan Mini]

On Dec 1, 2003, at 10:15 PM, Scott Long wrote:

> Jonathan Mini wrote:
>> I have found that the cost of printing the spew often
>> slows down compiles measurably, especially when spewing
>> to an xterm running on a local XFree86 process.  Even
>> with syscons, this is noticeable.
>> I generally tend to run my builds behind the screen
>> port these days, which  helps (screen implements a
>> virtual display buffer that disconnects screen updates
>> from the display client and the slave pty).  Another
>> optimization worth noting is running make -q, which
>> silences a lot of that spam (urban legend has it that
>> the synchronization in parallel makes to write the build
>> messages causes noticeable amounts of contention).
>
> I regularly use -s.  With the pipe code being completely
> Giant-free, I don't see a significant performance difference
> anymore on an SMP machine when the output is not supressed.

Ah, I meant -s.  And, that is good news.  I am still running
on a 4.x system most of the time, and (sigh) Linux 2.4.x the
rest of the time.

-- 
Jonathan Mini
mini at freebsd.org
http://www.freebsd.org