From: Jesper Dangaard Brouer <brouer@redhat.com>
To: Mel Gorman <mgorman@techsingularity.net>
Cc: Alexander Duyck <alexander.duyck@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
Chuck Lever <chuck.lever@oracle.com>,
Christoph Hellwig <hch@infradead.org>,
Matthew Wilcox <willy@infradead.org>,
LKML <linux-kernel@vger.kernel.org>,
Linux-Net <netdev@vger.kernel.org>, Linux-MM <linux-mm@kvack.org>,
Linux-NFS <linux-nfs@vger.kernel.org>,
brouer@redhat.com
Subject: Re: [PATCH 7/7] net: page_pool: use alloc_pages_bulk in refill code path
Date: Mon, 15 Mar 2021 09:40:38 +0100 [thread overview]
Message-ID: <20210315094038.22d6d79a@carbon> (raw)
In-Reply-To: <20210313133058.GZ3697@techsingularity.net>
On Sat, 13 Mar 2021 13:30:58 +0000
Mel Gorman <mgorman@techsingularity.net> wrote:
> On Fri, Mar 12, 2021 at 11:44:09AM -0800, Alexander Duyck wrote:
> > > - /* FUTURE development:
> > > - *
> > > - * Current slow-path essentially falls back to single page
> > > - * allocations, which doesn't improve performance. This code
> > > - * need bulk allocation support from the page allocator code.
> > > - */
> > > -
> > > - /* Cache was empty, do real allocation */
> > > -#ifdef CONFIG_NUMA
> > > - page = alloc_pages_node(pool->p.nid, gfp, pool->p.order);
> > > -#else
> > > - page = alloc_pages(gfp, pool->p.order);
> > > -#endif
> > > - if (!page)
> > > + if (unlikely(!__alloc_pages_bulk(gfp, pp_nid, NULL, bulk, &page_list)))
> > > return NULL;
> > >
> > > + /* First page is extracted and returned to caller */
> > > + first_page = list_first_entry(&page_list, struct page, lru);
> > > + list_del(&first_page->lru);
> > > +
> >
> > This seems kind of broken to me. If you pull the first page and then
> > cannot map it you end up returning NULL even if you placed a number of
> > pages in the cache.
> >
>
> I think you're right but I'm punting this to Jesper to fix. He's more
> familiar with this particular code and can verify the performance is
> still ok for high speed networks.
Yes, I'll take a look at this, and updated the patch accordingly (and re-run
the performance tests).
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
LinkedIn: http://www.linkedin.com/in/brouer
next prev parent reply other threads:[~2021-03-15 8:41 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-12 15:43 [PATCH 0/7 v4] Introduce a bulk order-0 page allocator with two in-tree users Mel Gorman
2021-03-12 15:43 ` [PATCH 1/7] mm/page_alloc: Move gfp_allowed_mask enforcement to prepare_alloc_pages Mel Gorman
2021-03-19 16:11 ` Vlastimil Babka
2021-03-19 17:49 ` Mel Gorman
2021-03-12 15:43 ` [PATCH 2/7] mm/page_alloc: Rename alloced to allocated Mel Gorman
2021-03-19 16:22 ` Vlastimil Babka
2021-03-12 15:43 ` [PATCH 3/7] mm/page_alloc: Add a bulk page allocator Mel Gorman
2021-03-19 18:18 ` Vlastimil Babka
2021-03-22 8:30 ` Mel Gorman
2021-03-12 15:43 ` [PATCH 4/7] SUNRPC: Set rq_page_end differently Mel Gorman
2021-03-12 15:43 ` [PATCH 5/7] SUNRPC: Refresh rq_pages using a bulk page allocator Mel Gorman
2021-03-12 18:44 ` Alexander Duyck
2021-03-12 19:22 ` Chuck Lever III
2021-03-13 12:59 ` Mel Gorman
2021-03-12 15:43 ` [PATCH 6/7] net: page_pool: refactor dma_map into own function page_pool_dma_map Mel Gorman
2021-03-12 15:43 ` [PATCH 7/7] net: page_pool: use alloc_pages_bulk in refill code path Mel Gorman
2021-03-12 19:44 ` Alexander Duyck
2021-03-12 20:05 ` Ilias Apalodimas
2021-03-15 13:39 ` Jesper Dangaard Brouer
2021-03-13 13:30 ` Mel Gorman
2021-03-15 8:40 ` Jesper Dangaard Brouer [this message]
2021-03-15 19:33 ` [PATCH mel-git] Followup: Update [PATCH 7/7] in Mel's series Jesper Dangaard Brouer
2021-03-15 19:33 ` [PATCH mel-git] net: page_pool: use alloc_pages_bulk in refill code path Jesper Dangaard Brouer
2021-03-17 16:31 ` [PATCH 0/7 v4] Introduce a bulk order-0 page allocator with two in-tree users Alexander Lobakin
2021-03-17 16:38 ` Jesper Dangaard Brouer
2021-03-17 16:52 ` Alexander Lobakin
2021-03-17 17:19 ` Jesper Dangaard Brouer
2021-03-17 22:25 ` Alexander Lobakin
Reply instructions:
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:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210315094038.22d6d79a@carbon \
--to=brouer@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=alexander.duyck@gmail.com \
--cc=chuck.lever@oracle.com \
--cc=hch@infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-nfs@vger.kernel.org \
--cc=mgorman@techsingularity.net \
--cc=netdev@vger.kernel.org \
--cc=willy@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* 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).