On Sat, 19 Mar 2016 13:13:59 +0100, Alexander Potapenko said: > Which GCC version were you using? Are you sure it didn't accidentally > enable the outline instrumentation (e.g. if the compiler is too old)? gcc --version gcc (GCC) 6.0.0 20160311 (Red Hat 6.0.0-0.16) * Fri Mar 11 2016 Jakub Jelinek <jakub@xxxxxxxxxx> 6.0.0-0.15 - update from the trunk Doesn't get much newer than that.. :) (Hmm.. possibly *too* new?) > > and saw an *amazing* slowdown. > Have you tried earlier KASAN versions? Is this a recent regression? First time I'd tried it, so no comparison point.. > Was KASAN reporting anything between these lines? Sometimes a recurring > warning slows everything down. Nope, it didn't report a single thing. > How did it behave after the startup? Was it still slow? After seeing how long it took to get to a single-user prompt, I didn't investigate further. It took 126 seconds to get here: [ 126.937247] audit: type=1327 audit(1458268293.617:100): proctitle="/usr/sbin/sulogin" compared to the more usual: [ 29.249260] audit: type=1327 audit(1458326938.276:100): proctitle="/usr/sbin/sulogin" (In both cases, there's a 10-12 second pause for entering a LUKS passphrase, so we're looking at about 110 seconds with KASAN versus about 17-18 without.) > Which machine were you using? Was it a real device or a VM? Running native on a Dell Latitude laptop.... (Based on the fact that you're asking questions rather than just saying it's expected behavior, I'm guessing I've once again managed to find a corner case of some sort. I'm more than happy to troubleshoot, if you can provide hints of what to try...)
Attachment:
pgprJieKuQTMP.pgp
Description: PGP signature