From: "Michael S. Tsirkin" <mst@redhat.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
Andrew Morton <akpm@linux-foundation.org>,
Huang Ying <ying.huang@intel.com>,
Jonathan Corbet <corbet@lwn.net>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Thorsten Leemhuis <regressions@leemhuis.info>,
stable <stable@vger.kernel.org>, linux-mm <linux-mm@kvack.org>
Subject: Re: [PATCH v2 1/3] mm/gup_benchmark: handle gup failures
Date: Sun, 8 Apr 2018 06:12:13 +0300 [thread overview]
Message-ID: <20180408060935-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <CA+55aFywfktB83dERzYaC1NCYxD+Lg+NRft5ypjmbbcM_qdxpQ@mail.gmail.com>
On Sat, Apr 07, 2018 at 01:08:43PM -0700, Linus Torvalds wrote:
> On Thu, Apr 5, 2018 at 2:03 PM, Michael S. Tsirkin <mst@redhat.com> wrote:
> >
> > nr = get_user_pages_fast(addr, nr, gup->flags & 1, pages + i);
> > - i += nr;
> > + if (nr > 0)
> > + i += nr;
>
> Can we just make this robust while at it, and just make it
>
> if (nr <= 0)
> break;
>
> instead? Then it doesn't care about zero vs negative error, and
> wouldn't get stuck in an endless loop if it got zero.
>
> Linus
I don't mind though it alredy breaks out on the next cycle:
if (nr != gup->nr_pages_per_call)
break;
the only issue is i getting corrupted when nr < 0;
next prev parent reply other threads:[~2018-04-08 3:12 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1522962072-182137-1-git-send-email-mst@redhat.com>
2018-04-05 21:03 ` [PATCH v2 1/3] mm/gup_benchmark: handle gup failures Michael S. Tsirkin
2018-04-07 20:08 ` Linus Torvalds
2018-04-08 3:12 ` Michael S. Tsirkin [this message]
2018-04-10 0:38 ` Andrew Morton
2018-04-05 21:03 ` [PATCH v2 2/3] gup: return -EFAULT on access_ok failure Michael S. Tsirkin
2018-04-05 21:03 ` [PATCH v2 3/3] mm/gup: document return value Michael S. Tsirkin
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