This is a replicate of http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=692053 to track down this issue in Gentoo as upstream won't fix it and patches for Debian have been provided.
Created attachment 349494 [details, diff] Port of fix-gc-hang-on-large-pages.patch from Stephan Schreiber on Debian Patches of Gentoo bug 471622 must be applied first and are required to fix this issue.
Created attachment 349496 [details] Updated firefox-10.0.11.ebuild, including required patches from Gentoo bug 471622
Dear maintainer, Would you please add patch as attachment 349494 [details, diff] to www-client/firefox/files folder (feel free to reformat if needed)? I've also provided as attachment 349496 [details] an updated firefox-10.0.11.ebuild including required patches from Gentoo bug 471622 to fix this issue. Thanks, Émeric
I just added the patches to the patchset and bumped the patchset version in the ebuild. Thanks Émeric!