Messages in this thread | | | From | Thomas Gleixner <> | Subject | Re: WARNING: suspicious RCU usage in idtentry_exit | Date | Fri, 29 May 2020 10:51:25 +0200 |
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Dmitry,
Dmitry Vyukov <dvyukov@google.com> writes: > On Thu, May 28, 2020 at 10:48 PM Paul E. McKenney <paulmck@kernel.org> wrote: >> On Thu, May 28, 2020 at 10:19:02PM +0200, Thomas Gleixner wrote: >> OK, from the .config, another suggestion is to build the kernel >> with CONFIG_RCU_EQS_DEBUG=y. This still requires that this issue be >> reproduced, but it might catch the problem earlier. > > How much does it slow down execution? If we enable it on syzbot, it > will affect all fuzzing done by syzbot always. > It can tolerate significant slowdown and it's far from a production > kernel (it enables KASAN, KCOV, LOCKDEP and more). But I am still > asking because some debugging features are built without performance > in mind at all (like let's just drop a global lock in every > kmalloc/free, which may be too much even for a standard debug build).
It's not worse than lockdep.
Thanks,
tglx
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