Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1466407
| From | Michal Hocko <mhocko@kernel.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [RFC PATCH] kernel/fork: fix CLONE_CHILD_CLEARTID regression in nscd |
| Date | 2016-08-19 15:30 +0200 |
| Message-ID | <s7S1Y-68X-27@gated-at.bofh.it> (permalink) |
| References | <s1iXf-5ai-19@gated-at.bofh.it> <s2bAm-7Up-13@gated-at.bofh.it> <s5hge-8nx-23@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Fri 12-08-16 11:41:13, Michal Hocko wrote:
> On Wed 03-08-16 23:08:04, Oleg Nesterov wrote:
> > sorry for delay, I am travelling till the end of the week.
>
> Same here...
>
> > On 08/01, Michal Hocko wrote:
[...]
> > > We should also check for vfork because
> > > this is killable since d68b46fe16ad ("vfork: make it killable").
> >
> > Hmm, why? Can't understand... In any case this check doesn't look right, the
> > comment says "a killed vfork parent" while tsk->vfork_done != NULL means it
> > is a vforked child.
> >
> > So if we want this change, why we can't simply do
> >
> > - if (!(tsk->flags & PF_SIGNALED) &&
> > + if (!(tsk->signal->flags & SIGNAL_GROUP_COREDUMP) &&
> >
> > ?
>
> This is what I had initially. But then the comment above the check made
> me worried that the parent of vforked child might get confused if the
> flag is cleared. I might have completely misunderstood the point of the
> comment though. So if you believe that vfork_done check is incorrect I
> can drop it. It shouldn't have any effect on the nscd usecase AFAIU.
So should I drop the vfork check and repost or we do not care about this
"regression" and declare nscd broken because it relies on a behavior
which is not in fact guaranteed by the kernel?
--
Michal Hocko
SUSE Labs
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
Re: [RFC PATCH] kernel/fork: fix CLONE_CHILD_CLEARTID regression in nscd Michal Hocko <mhocko@kernel.org> - 2016-08-12 11:50 +0200
Re: [RFC PATCH] kernel/fork: fix CLONE_CHILD_CLEARTID regression in nscd Michal Hocko <mhocko@kernel.org> - 2016-08-19 15:30 +0200
Re: [RFC PATCH] kernel/fork: fix CLONE_CHILD_CLEARTID regression in nscd Oleg Nesterov <oleg@redhat.com> - 2016-08-23 17:30 +0200
Re: [RFC PATCH] kernel/fork: fix CLONE_CHILD_CLEARTID regression in nscd Michal Hocko <mhocko@kernel.org> - 2016-08-23 18:20 +0200
csiph-web