use MALLOC_PERTURB_ ... or lose
sandeen at redhat.com
Wed May 5 17:28:49 UTC 2010
On 05/05/2010 12:21 PM, David Malcolm wrote:
> On Wed, 2010-05-05 at 18:24 +0200, Michal Schmidt wrote:
>> On Wed, 05 May 2010 17:30:29 +0200 Jim Meyering wrote:
>>> I propose (seriously, now) to add this to /etc/profile,
>>> or to some always-sourced file like /etc/profile.d/glibc.sh:
>>> # Enable glibc's malloc perturbing feature in Rawhide.
>>> # http://udrepper.livejournal.com/11429.html
>>> read _f _r _n _code_name < /etc/redhat-release &&
>>> case $_code_name in
>>> *Rawhide*) export MALLOC_PERTURB_=$((RANDOM % 255 + 1)) ;;
>> Would export MALLOC_CHECK_=3 be a useful addition too?
> I like the idea of rawhide-only debug checks like this, but can we add
> some kind of message to login like this:
Agreed, I'm tired of (insert random benchmarking site) saying "OH NOES!
Fedora got SLOWER AGAIN!" when it's really a lot of debug going on.
Stating something like this clearly on login & install would be nice,
not just for this MALLOC_PERTURB_ change but in general.
> This is a pre-release version of Fedora, and is running with extra
> diagnostics that help find bugs, but impact performance.
> Please read
> (LINK TO A WIKI PAGE)
> before attempting to run benchmarks on this system.
> Is there a good place to add this? e.g. /etc/issue ? I'm not sure of
> how to handle a conditional there.
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