From: Philip Li <philip.li@intel.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: kernel test robot <lkp@intel.com>,
Linux Memory Management List <linux-mm@kvack.org>,
Chinwen Chang <chinwen.chang@mediatek.com>
Subject: Re: [linux-next:master] BUILD REGRESSION 605cbf3d5f20470ec303b79feda3202935f4a142
Date: Sun, 23 Aug 2020 11:41:05 +0800 [thread overview]
Message-ID: <20200823034105.GA2953@intel.com> (raw)
In-Reply-To: <20200820134305.baa5ac2c1300a6b412a0c7c9@linux-foundation.org>
On Thu, Aug 20, 2020 at 01:43:05PM -0700, Andrew Morton wrote:
> On Fri, 21 Aug 2020 04:26:12 +0800 kernel test robot <lkp@intel.com> wrote:
>
> > tree/branch: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> > branch HEAD: 605cbf3d5f20470ec303b79feda3202935f4a142 Add linux-next specific files for 20200820
> >
> > Error/Warning in current branch:
>
> > ...
> >
> >
> > fs/proc/task_mmu.c:947 show_smaps_rollup() error: double unlocked 'mm->mmap_lock' (orig line 879)
>
> This is code added by "mm: proc: smaps_rollup: do not stall write
> attempts on mmap_lock"
> (http://lkml.kernel.org/r/1597715898-3854-4-git-send-email-chinwen.chang@mediatek.com).
>
> I don't get it.
Sorry Andrew, this is a false positive. We wrongly send out a few false reports
related to "double unlocked" due to bot issue. Sorry for the inconvenience caused.
>
> : if (mmap_lock_is_contended(mm)) {
> : mmap_read_unlock(mm);
> : ret = mmap_read_lock_killable(mm);
> : if (ret) {
> : release_task_mempolicy(priv);
> : goto out_put_mm;
> : }
>
> Here the mmap_lock is again taken for read
>
> : ...
> :
> : }
> : /* Case 2 above */
> : vma = vma->vm_next;
> : }
> :
> : ...
> :
> : mmap_read_unlock(mm);
>
> and here it's unlocked. I don't see a possibility for double-unlock?
>
prev parent reply other threads:[~2020-08-23 3:43 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-20 20:26 kernel test robot
2020-08-20 20:40 ` Andrew Morton
2020-08-20 21:03 ` Amir Goldstein
2020-08-20 20:43 ` Andrew Morton
2020-08-23 3:41 ` Philip Li [this message]
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