On Fri, Feb 16, 2018 at 09:52:53 +0100, Michal Privoznik wrote: > On 02/16/2018 09:34 AM, Pavel Hrdina wrote: > > On Mon, Feb 12, 2018 at 01:16:28PM +0100, Michal Privoznik wrote: > >> On 02/12/2018 01:10 PM, Peter Krempa wrote: > >>> On Mon, Feb 12, 2018 at 11:52:49 +0100, Michal Privoznik wrote: > >>>> Sometimes we need the lock in virObjectLockable to be recursive. > >>>> Because of the nature of pthreads we don't need a special class > >>>> for that - the pthread_* APIs don't distinguish between normal > >>>> and recursive locks. > >>>> > >>>> Based-on-work-of: John Ferlan <jferlan@xxxxxxxxxx> > >>>> Signed-off-by: Michal Privoznik <mprivozn@xxxxxxxxxx> > >>>> --- > >>>> src/libvirt_private.syms | 1 + > >>>> src/util/virobject.c | 22 +++++++++++++++++++--- > >>>> src/util/virobject.h | 4 ++++ > >>>> 3 files changed, 24 insertions(+), 3 deletions(-) > >>>> > >>>> diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms > >>>> index 3b14d7d15..fcf378105 100644 > >>>> --- a/src/libvirt_private.syms > >>>> +++ b/src/libvirt_private.syms [...] > This can be viewed as rewrite of existing code, not completely new code. > > > > > I know that NWFilter code is complex and removing recursive locks is > > not an easy task, but for the long run I think it's worth it, it will > > make the code cleaner and easier to follow. > > Right, that the ideal goal. But as I said it's far from happening. I > think it was you who when trying to fix some issue in NWFilter drew call > graph in NWFilter driver and realized how complicated it is. That's why > I don't see it happening anywhere in near future. Also, if we really > have multiple entry points as Dan mentioned earlier can we really fix > this? I mean there are multiple locks that need to be acquired when > touching a virNWFilterObj. The advantage of reentrant mutex is that we > will not get a dead lock scenario if two functions fight over lock. > > Anyway, it's a pity that we are stuck on this patch while reworking the > vir*ObjList code. So and why can't we keep the NWfilter code as-is until the locking is sanitized first? It is working so I don't see a reason to try to rewrite it to objects if it is not trivially possible.
Attachment:
signature.asc
Description: PGP signature
-- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list
