Messages in this thread | | | Date | Mon, 29 Feb 2016 19:10:19 +0100 | From | Oleg Nesterov <> | Subject | Re: [PATCH 13/18] exec: make exec path waiting for mmap_sem killable |
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On 02/29, Michal Hocko wrote: > > On Mon 29-02-16 18:23:34, Oleg Nesterov wrote: > > On 02/29, Michal Hocko wrote: > > > > > > @@ -267,7 +267,10 @@ static int __bprm_mm_init(struct linux_binprm *bprm) > > > if (!vma) > > > return -ENOMEM; > > > > > > - down_write(&mm->mmap_sem); > > > + if (down_write_killable(&mm->mmap_sem)) { > > > + err = -EINTR; > > > + goto err_free; > > > + } > > > vma->vm_mm = mm; > > > > I won't argue, but this looks unnecessary. Nobody else can see this new mm, > > down_write() can't block. > > > > In fact I think we can just remove down_write/up_write here. Except perhaps > > there is lockdep_assert_held() somewhere in these paths. > > This is what I had initially but then I've noticed that mm_alloc() does > mm_init(current)->init_new_context(current)
yes, and init_new_context() is arch dependant...
> code doesn't seem much harder to follow, the callers are already > handling all error paths so I guess it would be better to simply move on > this.
Yes, agreed, please forget.
Oleg.
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