From: Jens Axboe <axboe@kernel.dk>
To: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-aio@kvack.org, hch@lst.de
Subject: Re: [PATCH 24/27] block: implement bio helper to add iter kvec pages to bio
Date: Fri, 30 Nov 2018 13:32:21 -0700 [thread overview]
Message-ID: <1545b364-df01-51e7-1786-56dde7c49b5d@kernel.dk> (raw)
In-Reply-To: <6e42d763-9c94-6b84-7099-f5ef5964404c@kernel.dk>
On 11/30/18 1:15 PM, Jens Axboe wrote:
> On 11/30/18 12:21 PM, Al Viro wrote:
>> On Fri, Nov 30, 2018 at 09:56:43AM -0700, Jens Axboe wrote:
>>> For an ITER_KVEC, we can just iterate the iov and add the pages
>>> to the bio directly.
>>
>>> + page = virt_to_page(kv->iov_base);
>>> + size = bio_add_page(bio, page, kv->iov_len,
>>> + offset_in_page(kv->iov_base));
>>
>> Who said that you *can* do virt_to_page() on those? E.g. vmalloc()'ed
>> addresses are fine for ITER_KVEC, etc.
>
> Then how do you set up a kvec based iter with memory you can safely
> DMA to/from?
Would this make you happy:
if (!is_vmalloc_addr(kv->iov_base))
page = virt_to_page(kv->iov_base);
else
page = vmalloc_to_page(kv->iov_base);
--
Jens Axboe
next prev parent reply other threads:[~2018-11-30 20:32 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-30 16:56 [PATCHSET v4] Support for polled aio Jens Axboe
2018-11-30 16:56 ` [PATCH 01/27] aio: fix failure to put the file pointer Jens Axboe
2018-11-30 17:07 ` Bart Van Assche
2018-11-30 17:08 ` Jens Axboe
2018-11-30 17:24 ` Bart Van Assche
2018-11-30 16:56 ` [PATCH 02/27] aio: clear IOCB_HIPRI Jens Axboe
2018-11-30 17:13 ` Christoph Hellwig
2018-11-30 17:14 ` Jens Axboe
2018-12-04 14:46 ` Christoph Hellwig
2018-12-04 16:40 ` Jens Axboe
2018-11-30 16:56 ` [PATCH 03/27] fs: add an iopoll method to struct file_operations Jens Axboe
2018-11-30 16:56 ` [PATCH 04/27] block: wire up block device iopoll method Jens Axboe
2018-11-30 16:56 ` [PATCH 05/27] block: ensure that async polled IO is marked REQ_NOWAIT Jens Axboe
2018-11-30 17:12 ` Bart Van Assche
2018-11-30 17:17 ` Jens Axboe
2018-12-04 14:48 ` Christoph Hellwig
2018-12-04 18:13 ` Jens Axboe
2018-11-30 16:56 ` [PATCH 06/27] iomap: wire up the iopoll method Jens Axboe
2018-11-30 16:56 ` [PATCH 07/27] iomap: ensure that async polled IO is marked REQ_NOWAIT Jens Axboe
2018-11-30 16:56 ` [PATCH 08/27] aio: use assigned completion handler Jens Axboe
2018-11-30 16:56 ` [PATCH 09/27] aio: separate out ring reservation from req allocation Jens Axboe
2018-11-30 16:56 ` [PATCH 10/27] aio: don't zero entire aio_kiocb aio_get_req() Jens Axboe
2018-12-04 14:49 ` Christoph Hellwig
2018-12-04 15:27 ` Jens Axboe
2018-11-30 16:56 ` [PATCH 11/27] aio: only use blk plugs for > 2 depth submissions Jens Axboe
2018-12-04 14:50 ` Christoph Hellwig
2018-11-30 16:56 ` [PATCH 12/27] aio: use iocb_put() instead of open coding it Jens Axboe
2018-12-04 14:50 ` Christoph Hellwig
2018-11-30 16:56 ` [PATCH 13/27] aio: split out iocb copy from io_submit_one() Jens Axboe
2018-11-30 16:56 ` [PATCH 14/27] aio: abstract out io_event filler helper Jens Axboe
2018-11-30 16:56 ` [PATCH 15/27] aio: add io_setup2() system call Jens Axboe
2018-11-30 16:56 ` [PATCH 16/27] aio: add support for having user mapped iocbs Jens Axboe
2018-11-30 16:56 ` [PATCH 17/27] aio: support for IO polling Jens Axboe
2018-11-30 16:56 ` [PATCH 18/27] aio: add submission side request cache Jens Axboe
2018-11-30 16:56 ` [PATCH 19/27] fs: add fget_many() and fput_many() Jens Axboe
2018-11-30 16:56 ` [PATCH 20/27] aio: use fget/fput_many() for file references Jens Axboe
2018-11-30 16:56 ` [PATCH 21/27] aio: split iocb init from allocation Jens Axboe
2018-11-30 16:56 ` [PATCH 22/27] aio: batch aio_kiocb allocation Jens Axboe
2018-11-30 16:56 ` [PATCH 23/27] block: add BIO_HOLD_PAGES flag Jens Axboe
2018-11-30 16:56 ` [PATCH 24/27] block: implement bio helper to add iter kvec pages to bio Jens Axboe
2018-11-30 19:21 ` Al Viro
2018-11-30 20:15 ` Jens Axboe
2018-11-30 20:32 ` Jens Axboe [this message]
2018-11-30 21:11 ` Al Viro
2018-11-30 21:16 ` Jens Axboe
2018-11-30 21:25 ` Al Viro
2018-11-30 21:34 ` Jens Axboe
2018-11-30 22:06 ` Jens Axboe
2018-12-04 14:55 ` Christoph Hellwig
2018-12-04 15:25 ` Jens Axboe
2018-11-30 16:56 ` [PATCH 25/27] fs: add support for mapping an ITER_KVEC for O_DIRECT Jens Axboe
2018-11-30 16:56 ` [PATCH 26/27] iov_iter: add import_kvec() Jens Axboe
2018-11-30 19:17 ` Al Viro
2018-11-30 20:15 ` Jens Axboe
2018-11-30 16:56 ` [PATCH 27/27] aio: add support for pre-mapped user IO buffers Jens Axboe
2018-11-30 21:44 ` Jeff Moyer
2018-11-30 21:57 ` Jens Axboe
2018-11-30 22:04 ` Jeff Moyer
2018-11-30 22:11 ` Jens Axboe
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