From: Jason Gunthorpe <jgg@nvidia.com>
To: David Hildenbrand <david@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>,
Alistair Popple <apopple@nvidia.com>,
Christoph Hellwig <hch@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>,
LKML <linux-kernel@vger.kernel.org>,
linux-mm@kvack.org, linux-stable@vger.kernel.org,
Vivek Kasireddy <vivek.kasireddy@intel.com>,
Dave Airlie <airlied@redhat.com>,
Gerd Hoffmann <kraxel@redhat.com>,
Matthew Wilcox <willy@infradead.org>,
Peter Xu <peterx@redhat.com>, Arnd Bergmann <arnd@arndb.de>,
Daniel Vetter <daniel.vetter@ffwll.ch>,
Dongwon Kim <dongwon.kim@intel.com>,
Hugh Dickins <hughd@google.com>,
Junxiao Chang <junxiao.chang@intel.com>,
Mike Kravetz <mike.kravetz@oracle.com>,
Oscar Salvador <osalvador@suse.de>
Subject: Re: [PATCH] mm/gup: restore the ability to pin more than 2GB at a time
Date: Wed, 30 Oct 2024 09:04:53 -0300 [thread overview]
Message-ID: <20241030120453.GC6956@nvidia.com> (raw)
In-Reply-To: <bfee966f-807d-4668-b353-159a6e8066f2@redhat.com>
On Wed, Oct 30, 2024 at 09:34:51AM +0100, David Hildenbrand wrote:
> The unusual thing is not the amount of system memory we are pinning but *how
> many* pages we try pinning in the single call.
>
> If you stare at vfio_pin_pages_remote, we seem to be batching it.
>
> long req_pages = min_t(long, npage, batch->capacity);
>
> Which is
>
> #define VFIO_BATCH_MAX_CAPACITY (PAGE_SIZE / sizeof(struct page *))
>
> So you can fix this in your driver ;)
Yeah, everything batches that I'm aware of. RDMA also uses a 4k batch
size, and iommufd uses 64k.
Jason
next prev parent reply other threads:[~2024-10-30 12:05 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-10-30 3:01 John Hubbard
2024-10-30 4:21 ` Christoph Hellwig
2024-10-30 4:30 ` John Hubbard
2024-10-30 4:33 ` Christoph Hellwig
2024-10-30 4:39 ` John Hubbard
2024-10-30 4:42 ` Christoph Hellwig
2024-10-30 4:44 ` John Hubbard
2024-10-30 6:18 ` Alistair Popple
2024-10-30 6:50 ` John Hubbard
2024-10-30 8:34 ` David Hildenbrand
2024-10-30 9:01 ` David Hildenbrand
2024-10-30 18:34 ` John Hubbard
2024-10-31 0:02 ` Jason Gunthorpe
2024-10-31 0:17 ` John Hubbard
2024-10-31 0:25 ` Jason Gunthorpe
2024-10-31 0:47 ` John Hubbard
2024-10-30 12:04 ` Jason Gunthorpe [this message]
2024-10-30 17:25 ` John Hubbard
2024-10-30 11:59 ` Jason Gunthorpe
2024-10-30 11:03 ` Vlastimil Babka
2024-10-30 17:29 ` John Hubbard
2024-10-30 17:42 ` Vlastimil Babka
2024-10-30 17:49 ` John Hubbard
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