On Thu, Jul 9, 2009 at 5:06 PM, Jakub Jelinek <[email protected]> wrote:
> On Thu, Jul 09, 2009 at 10:32:01AM -0400, Matthew Miller wrote: > > Apparently there was some fun with prelink breaking everything in rawhide > > recently: <https://bugzilla.redhat.com/show_bug.cgi?id=509655>. I didn't > > notice, because like Pete Zaitcev says in the comments, removing prelink > is > > one of the first things I do. > > > > I see it as adding unnecessary complexity and fragility, and it makes > > forensic verification difficult. Binaries can't be verified without being > > modified, which is far from ideal. And the error about dependencies > having > > changed since prelinking is disturbingly frequent. > > > > On the other hand, smart people have worked on it. It's very likely that > > those smart people know things I don't. I can't find any good numbers > > anywhere demonstrating the concrete benefits provided by prelink. Is > there > > data out there? Pretty charts and graphs would be nice. The only things > I've > > been able to find are old and not very impressive: > > > > <http://crast.us/james/articles/prelink.php> > > < > http://smackerelofopinion.blogspot.com/2009/06/does-prelinking-speed-up-boot-times.html > > > > <http://reallylongword.org/prelink-2/> > > Say on x86-64 F11 (with /etc/prelink.conf.d/nss-prelink.conf removed): > LD_DEBUG=statistics /usr/lib64/openoffice.org3/program/swriter.bin > 11799: > 11799: runtime linker statistics: > 11799: total startup time in dynamic loader: 18632372 clock > cycles > 11799: time needed for relocation: 2975643 clock cycles > (15.9%) > 11799: number of relocations: 0 > 11799: number of relocations from cache: 1527 > 11799: number of relative relocations: 0 > 11799: time needed to load objects: 13190177 clock > cycles (70.7%) > LD_USE_LOAD_BIAS=0 LD_DEBUG=statistics > /usr/lib64/openoffice.org3/program/swriter.bin > 11817: > 11817: runtime linker statistics: > 11817: total startup time in dynamic loader: 145813250 clock > cycles > 11817: time needed for relocation: 129375884 clock > cycles (88.7%) > 11817: number of relocations: 42207 > 11817: number of relocations from cache: 126013 > 11817: number of relative relocations: 149959 > 11817: time needed to load objects: 15248893 clock > cycles (10.4%) > The former is how long it takes before swriter.bin starts up when > prelinked, > the latter tells it not to use prelink information and do normal > relocation. > Try this on any other GUI app that links against dozens of shared > libraries. Perfect. this is the key point for me. If i mantain server only, not desktop client, without X and the like, no problem to disable it. Isn't right ? I have already do this, for security reason due to centralizzated integrity checker, on +300 production RHEL machine. Regards > > -- > fedora-devel-list mailing list > [email protected] > https://www.redhat.com/mailman/listinfo/fedora-devel-list >
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