From: Andrew Morton <akpm@linux-foundation.org>
To: Arjun Roy <arjunroy.kdev@gmail.com>
Cc: davem@davemloft.net, netdev@vger.kernel.org, linux-mm@kvack.org,
arjunroy@google.com, Eric Dumazet <edumazet@google.com>,
Soheil Hassas Yeganeh <soheil@google.com>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [PATCH resend mm,net-next 2/3] mm: Add vm_insert_pages().
Date: Wed, 12 Feb 2020 18:41:01 -0800 [thread overview]
Message-ID: <20200212184101.b8551710bd19c8216d62290d@linux-foundation.org> (raw)
In-Reply-To: <20200128025958.43490-2-arjunroy.kdev@gmail.com>
On Mon, 27 Jan 2020 18:59:57 -0800 Arjun Roy <arjunroy.kdev@gmail.com> wrote:
> Add the ability to insert multiple pages at once to a user VM with
> lower PTE spinlock operations.
>
> The intention of this patch-set is to reduce atomic ops for
> tcp zerocopy receives, which normally hits the same spinlock multiple
> times consecutively.
Seems sensible, thanks. Some other vm_insert_page() callers might want
to know about this, but I can't immediately spot any which appear to be
high bandwidth.
Is there much point in keeping the vm_insert_page() implementation
around? Replace it with
static inline int
vm_insert_page(struct vm_area_struct *vma, unsigned long addr,
struct page *page)
{
return vm_insert_pages(vma, addr, &page, 1);
}
?
Also, vm_insert_page() does
if (!page_count(page))
return -EINVAL;
and this was not carried over into vm_insert_pages(). How come?
I don't know what that test does - it was added by Linus in the
original commit a145dd411eb28c83. It's only been 15 years so I'm sure
he remembers ;)
next prev parent reply other threads:[~2020-02-13 2:41 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-28 2:59 [PATCH resend mm,net-next 1/3] mm: Refactor insert_page to prepare for batched-lock insert Arjun Roy
2020-01-28 2:59 ` [PATCH resend mm,net-next 2/3] mm: Add vm_insert_pages() Arjun Roy
2020-02-13 2:41 ` Andrew Morton [this message]
2020-02-13 17:09 ` Arjun Roy
2020-02-13 21:37 ` Linus Torvalds
2020-02-13 21:54 ` Matthew Wilcox
2020-02-13 22:06 ` Arjun Roy
2020-01-28 2:59 ` [PATCH resend mm,net-next 3/3] net-zerocopy: Use vm_insert_pages() for tcp rcv zerocopy Arjun Roy
2020-02-13 2:56 ` Andrew Morton
2020-02-17 2:49 ` Arjun Roy
2020-02-21 21:21 ` Arjun Roy
2020-02-24 3:37 ` Andrew Morton
2020-02-24 16:19 ` Arjun Roy
2020-04-10 19:04 ` Andrew Morton
2020-04-10 19:13 ` Arjun Roy
2020-04-10 19:15 ` Arjun Roy
2020-02-13 2:41 ` [PATCH resend mm,net-next 1/3] mm: Refactor insert_page to prepare for batched-lock insert Andrew Morton
2020-02-13 16:52 ` Arjun Roy
2020-02-13 16:55 ` Arjun Roy
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