From: Andrew Morton <firstname.lastname@example.org>
To: Mike Kravetz <email@example.com>
Cc: Matthew Wilcox <firstname.lastname@example.org>,
"Aneesh Kumar K.V" <email@example.com>,
Subject: Re: [RFC PATCH] mm/hugetlb: make hugetlb_lock irq safe
Date: Wed, 5 Sep 2018 15:00:08 -0700 [thread overview]
Message-ID: <firstname.lastname@example.org> (raw)
On Wed, 5 Sep 2018 14:35:11 -0700 Mike Kravetz <email@example.com> wrote:
> > so perhaps we could put some
> > stopgap workaround into that site and add a runtime warning into the
> > put_page() code somewhere to detect puttage of huge pages from hardirq
> > and softirq contexts.
> I think we would add the warning/etc at free_huge_page. The issue would
> only apply to hugetlb pages, not THP.
> But, the more I think about it the more I think Aneesh's patch to do
> spin_lock/unlock_irqsave is the right way to go. Currently, we only
> know of one place where a put_page of hugetlb pages is done from softirq
> context. So, we could take the spin_lock/unlock_bh as Matthew suggested.
> When the powerpc iommu code was added, I doubt this was taken into account.
> I would be afraid of someone adding put_page from hardirq context.
Me too. If we're going to do this, surely we should make hugepages
behave in the same fashion as PAGE_SIZE pages.
next prev parent reply other threads:[~2018-09-05 22:00 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-05 11:23 [RFC PATCH] mm/hugetlb: make hugetlb_lock irq safe Aneesh Kumar K.V
2018-09-05 13:04 ` Matthew Wilcox
2018-09-05 13:26 ` Aneesh Kumar K.V
2018-09-05 13:48 ` Matthew Wilcox
2018-09-05 19:58 ` Andrew Morton
2018-09-05 21:35 ` Mike Kravetz
2018-09-05 22:00 ` Andrew Morton [this message]
2018-09-05 23:07 ` Matthew Wilcox
2018-09-05 23:51 ` Mike Kravetz
2018-09-06 4:03 ` Aneesh Kumar K.V
2018-09-06 11:19 ` Michal Hocko
2018-09-06 3:58 ` Aneesh Kumar K.V
2018-09-06 3:54 ` Aneesh Kumar K.V
2018-09-06 4:00 ` Aneesh Kumar K.V
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).