From: Christoph Hellwig <hch@lst.de>
To: Leon Romanovsky <leon@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>,
Doug Ledford <dledford@redhat.com>,
Jason Gunthorpe <jgg@nvidia.com>,
Maor Gottlieb <maorg@nvidia.com>,
linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org
Subject: Re: [PATCH rdma-next 1/4] lib/scatterlist: Refactor sg_alloc_table_from_pages
Date: Mon, 7 Sep 2020 09:29:12 +0200 [thread overview]
Message-ID: <20200907072912.GA19875@lst.de> (raw)
In-Reply-To: <20200903155434.1153934-1-leon@kernel.org>
On Thu, Sep 03, 2020 at 06:54:34PM +0300, Leon Romanovsky wrote:
> From: Maor Gottlieb <maorg@nvidia.com>
>
> Currently, sg_alloc_table_from_pages doesn't support dynamic chaining of
> SG entries. Therefore it requires from user to allocate all the pages in
> advance and hold them in a large buffer. Such a buffer consumes a lot of
> temporary memory in HPC systems which do a very large memory registration.
>
> The next patches introduce API for dynamically allocation from pages and
> it requires us to do the following:
> * Extract the code to alloc_from_pages_common.
> * Change the build of the table to iterate on the chunks and not on the
> SGEs. It will allow dynamic allocation of more SGEs.
>
> Since sg_alloc_table_from_pages allocate exactly the number of chunks,
> therefore chunks are equal to the number of SG entries.
Given how few users __sg_alloc_table_from_pages has, what about just
switching it to your desired calling conventions without another helper?
next prev parent reply other threads:[~2020-09-07 7:29 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-03 12:18 [PATCH rdma-next 0/4] scatterlist: add sg_alloc_table_append function Leon Romanovsky
2020-09-03 12:18 ` [PATCH rdma-next 2/4] lib/scatterlist: Add support in dynamically allocation of SG entries Leon Romanovsky
2020-09-07 7:29 ` Christoph Hellwig
2020-09-07 12:34 ` Maor Gottlieb
2020-09-03 12:18 ` [PATCH rdma-next 3/4] lib/scatterlist: Add support in dynamic allocation of SG table from pages Leon Romanovsky
2020-09-07 7:29 ` Christoph Hellwig
2020-09-07 12:44 ` Maor Gottlieb
2020-09-08 15:54 ` Christoph Hellwig
2020-09-08 16:13 ` Jason Gunthorpe
2020-09-03 12:18 ` [PATCH rdma-next 4/4] RDMA/umem: Move to allocate " Leon Romanovsky
2020-09-07 7:29 ` Christoph Hellwig
2020-09-08 14:10 ` Jason Gunthorpe
2020-09-03 15:32 ` [PATCH rdma-next 0/4] scatterlist: add sg_alloc_table_append function Christoph Hellwig
2020-09-03 15:55 ` Leon Romanovsky
2020-09-03 15:54 ` [PATCH rdma-next 1/4] lib/scatterlist: Refactor sg_alloc_table_from_pages Leon Romanovsky
2020-09-07 7:29 ` Christoph Hellwig [this message]
2020-09-07 12:32 ` Maor Gottlieb
2020-09-08 15:52 ` Christoph Hellwig
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