Date: Wed, 27 Nov 2019 18:57:21 +0000 From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 242272] LinuxKPI combines all RCU and SRCU domains together, leading to deadlock Message-ID: <bug-242272-227@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=242272 Bug ID: 242272 Summary: LinuxKPI combines all RCU and SRCU domains together, leading to deadlock Product: Base System Version: CURRENT Hardware: Any OS: Any Status: New Severity: Affects Some People Priority: --- Component: kern Assignee: bugs@FreeBSD.org Reporter: aboyer@pensando.io In that other OS, all RCU code is in the one domain, and each SRCU user gets its own domain. (More or less.) They are all combined together in FreeBSD since it has only a bare-bones implementation in the KPI. This is a problem because ib_uverbs holds an SRCU read lock when calling into the provider's destroy_cq function. Providers may expect to be able to use RCU primitives when tearing down, but calling synchronize_rcu() or synchronize_srcu() will lead to a deadlock, even on a completely separate SRCU domain. To fix this will require adding real multiple-domain support to the KPI. -- You are receiving this mail because: You are the assignee for the bug.
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