Hi, On Fri, Aug 11, 2017 at 09:46:29AM -0400, Blake Caldwell wrote: > > On Tue, May 16, 2017 at 01:35:57PM +0300, Mike Rapoport wrote: > > > Hi, > > > > Any comments on this? > > Shall I repost without the "RFC" prefix? > > > I have a use case for this feature exactly like what you have described. The > process should be suspended until the event has been handled. I would like > to test this if there is a rebased patchset out there somewhere? I'm using > 4.13.0_rc3 from > https://kernel.googlesource.com/pub/scm/linux/kernel/git/andrea/aa.git > > I wasn't able to apply the patches without heavy modification (mostly patch > 3/5). I don't have a version rebased on Andrea's tree, sorry. > Thanks for the work on this. > > > These patches add ability to generate userfaultfd events so that thier > > > processing will be synchronized with the non-cooperative thread that > > > caused the event. > > > > > > In the non-cooperative case userfaultfd resumes execution of the > > > thread that caused an event when the notification is read() by the uffd > > monitor. > > > In some cases, like, for example, madvise(MADV_REMOVE), it might be > > > desirable to keep the thread that caused the event suspended until the > > > uffd monitor had the event handled. > > > > > > The first two patches just shuffle the code a bit to make subsequent > > > changes easier. > > > The patches 3 and 4 create some unification in the way the threads are > > > queued into waitqueues either after page fault or after a > > > non-cooperative event. > > > The fifth patch extends the userfaultfd API with an implementation of > > > UFFD_EVENT_REMOVE_SYNC that allows to keep the thread that triggered > > > UFFD_EVENT_REMOVE until the uffd monitor would not wake it explicitly. > > > > > > Mike Rapoport (5): > > > userfaultfd: introduce userfault_init_waitqueue helper > > > userfaultfd: introduce userfaultfd_should_wait helper > > > userfaultfd: non-cooperative: generalize wake key structure > > > userfaultfd: non-cooperative: use fault_pending_wqh for all events > > > userfaultfd: non-cooperative: allow synchronous EVENT_REMOVE > > > > > > fs/userfaultfd.c | 205 > ++++++++++++++++++++++++--------------- > > > include/uapi/linux/userfaultfd.h | 11 +++ > > > 2 files changed, 136 insertions(+), 80 deletions(-) > > > > > > -- > > > 2.7.4 > > > > > > > -- > > To unsubscribe, send a message with 'unsubscribe linux-mm' in > > the body to majordomo@xxxxxxxxx. For more info on Linux MM, > > see: http://www.linux-mm.org/ . > > Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a> > -- Sincerely yours, Mike. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
