(Applies to kvm.git/master:4631e094) The following is the latest attempt to fix the races in irqfd/eventfd, as well as restore DEASSIGN support. For more details, please read the patch headers. I've restored the slow-work variant of the logic as a separate patch (5/5) so we can get a better idea of the true difference between the workqueue approach and the slow-work style. I am personally in favor of the slow-work approach since it doesnt require a mostly-idle+dedicated thread to hang around. But that is just me. 5/5 can be ignored, folded in to 3/5+4/5 as appropriate, or merged as is per the whim of Avi et. al. As always, this series has been tested against the kvm-eventfd unit test with both 5/5 applied and unapplied, and everything appears to be functioning properly. You can download this test here: ftp://ftp.novell.com/dev/ghaskins/kvm-eventfd.tar.bz2 I've included version 4 of Davide's eventfd patch (ported to kvm.git) so that its a complete reviewable series. Note, however, that there may be later versions of his patch to consider for merging, so we should coordinate with him. -Greg [Changelog: v7: *) Addressed minor-nit feedback from Michael *) Cleaned up patch headers *) Re-added separate slow-work feature patch to end for comparison v6: *) Removed slow-work in favor of using a dedicated single-thread workqueue. *) Condensed cleanup path to always use deferred shutdown *) Saved about 56 lines over v5, with the following diffstat: include/linux/kvm_host.h | 2 virt/kvm/eventfd.c | 248 ++++++++++++++++++----------------------------- 2 files changed, 97 insertions(+), 153 deletions(-) v5: Untracked.. ] --- Davide Libenzi (1): eventfd - revised interface and cleanups (4th rev) Gregory Haskins (4): KVM: Make irqfd use slow-work for shutdown KVM: add irqfd DEASSIGN feature KVM: Fix races in irqfd using new eventfd_kref_get interface kvm: prepare irqfd for having interrupts disabled during eventfd->release drivers/lguest/lg.h | 2 drivers/lguest/lguest_user.c | 4 - fs/aio.c | 24 +--- fs/eventfd.c | 126 ++++++++++++++++++---- include/linux/aio.h | 4 - include/linux/eventfd.h | 35 +++++- include/linux/kvm.h | 2 include/linux/kvm_host.h | 7 + virt/kvm/Kconfig | 1 virt/kvm/eventfd.c | 246 ++++++++++++++++++++++++++++++++---------- 10 files changed, 343 insertions(+), 108 deletions(-) -- Signature -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
