This document gives a brief rationale for the TREE_RCU-related test cases, a group that includes PREEMPT_RCU. Kconfig Parameters: CONFIG_DEBUG_LOCK_ALLOC -- Do three, covering CONFIG_PROVE_LOCKING & not. CONFIG_DEBUG_OBJECTS_RCU_HEAD -- Do one. CONFIG_HOTPLUG_CPU -- Do half. (Every second.) CONFIG_HZ_PERIODIC -- Do one. CONFIG_NO_HZ_IDLE -- Do those not otherwise specified. (Groups of two.) CONFIG_NO_HZ_FULL -- Do two, one with CONFIG_NO_HZ_FULL_SYSIDLE. CONFIG_NO_HZ_FULL_SYSIDLE -- Do one. CONFIG_PREEMPT -- Do half. (First three and #8.) CONFIG_PROVE_LOCKING -- Do several, covering CONFIG_DEBUG_LOCK_ALLOC=y and not. CONFIG_PROVE_RCU -- Hardwired to CONFIG_PROVE_LOCKING. CONFIG_RCU_BOOST -- one of PREEMPT_RCU. CONFIG_RCU_KTHREAD_PRIO -- set to 2 for _BOOST testing. CONFIG_RCU_FANOUT -- Cover hierarchy, but overlap with others. CONFIG_RCU_FANOUT_LEAF -- Do one non-default. CONFIG_RCU_FAST_NO_HZ -- Do one, but not with CONFIG_RCU_NOCB_CPU_ALL. CONFIG_RCU_NOCB_CPU -- Do three, see below. CONFIG_RCU_NOCB_CPU_ALL -- Do one. CONFIG_RCU_NOCB_CPU_NONE -- Do one. CONFIG_RCU_NOCB_CPU_ZERO -- Do one. CONFIG_RCU_TRACE -- Do half. CONFIG_SMP -- Need one !SMP for PREEMPT_RCU. !RCU_EXPERT -- Do a few, but these have to be vanilla configurations. RCU-bh: Do one with PREEMPT and one with !PREEMPT. RCU-sched: Do one with PREEMPT but not BOOST. Boot parameters: nohz_full - do at least one. maxcpu -- do at least one. rcupdate.rcu_self_test_bh -- Do at least one each, offloaded and not. rcupdate.rcu_self_test_sched -- Do at least one each, offloaded and not. rcupdate.rcu_self_test -- Do at least one each, offloaded and not. rcutree.rcu_fanout_exact -- Do at least one. Kconfig Parameters Ignored: CONFIG_64BIT Used only to check CONFIG_RCU_FANOUT value, inspection suffices. CONFIG_NO_HZ_FULL_SYSIDLE_SMALL Defer until Frederic uses this. CONFIG_PREEMPT_COUNT CONFIG_PREEMPT_RCU Redundant with CONFIG_PREEMPT, ignore. CONFIG_RCU_BOOST_DELAY Inspection suffices, ignore. CONFIG_RCU_CPU_STALL_TIMEOUT Inspection suffices, ignore. CONFIG_RCU_STALL_COMMON Implied by TREE_RCU and PREEMPT_RCU. CONFIG_RCU_TORTURE_TEST CONFIG_RCU_TORTURE_TEST_RUNNABLE Always used in KVM testing. CONFIG_PREEMPT_RCU CONFIG_TREE_RCU These are controlled by CONFIG_PREEMPT. p;id=433e19cf33d34bb6751c874a9c00980552fe508c'>diff
path: root/drivers/usb/host/ehci-xilinx-of.c
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authorDexuan Cui <decui@microsoft.com>2017-01-28 11:46:02 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-01-31 10:59:48 +0100
commit433e19cf33d34bb6751c874a9c00980552fe508c (patch)
treece6547ef2987fbb289fa28f03536328a42781651 /drivers/usb/host/ehci-xilinx-of.c
parent191e885a2e130e639bb0c8ee350d7047294f2ce6 (diff)
Drivers: hv: vmbus: finally fix hv_need_to_signal_on_read()
Commit a389fcfd2cb5 ("Drivers: hv: vmbus: Fix signaling logic in hv_need_to_signal_on_read()") added the proper mb(), but removed the test "prev_write_sz < pending_sz" when making the signal decision. As a result, the guest can signal the host unnecessarily, and then the host can throttle the guest because the host thinks the guest is buggy or malicious; finally the user running stress test can perceive intermittent freeze of the guest. This patch brings back the test, and properly handles the in-place consumption APIs used by NetVSC (see get_next_pkt_raw(), put_pkt_raw() and commit_rd_index()). Fixes: a389fcfd2cb5 ("Drivers: hv: vmbus: Fix signaling logic in hv_need_to_signal_on_read()") Signed-off-by: Dexuan Cui <decui@microsoft.com> Reported-by: Rolf Neugebauer <rolf.neugebauer@docker.com> Tested-by: Rolf Neugebauer <rolf.neugebauer@docker.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: <stable@vger.kernel.org> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/host/ehci-xilinx-of.c')