From: Jens Axboe <axboe@kernel.dk>
To: Christoph Hellwig <hch@infradead.org>
Cc: linux-fsdevel@vger.kernel.org, linux-aio@kvack.org,
linux-block@vger.kernel.org, hch@lst.de, viro@zeniv.linux.org.uk
Subject: Re: [PATCH 09/22] aio: add submission side request cache
Date: Thu, 27 Dec 2018 13:31:44 -0700 [thread overview]
Message-ID: <b930953e-0df3-5c85-bf5b-dd642339e50c@kernel.dk> (raw)
In-Reply-To: <20181227135656.GC25525@infradead.org>
On 12/27/18 6:56 AM, Christoph Hellwig wrote:
>> +/*
>> + * After the iocb has been issued, it's safe to be found on the poll list.
>> + * Adding the kiocb to the list AFTER submission ensures that we don't
>> + * find it from a io_getevents() thread before the issuer is done accessing
>> + * the kiocb cookie.
>> + */
>> +static void aio_iopoll_iocb_issued(struct aio_submit_state *state,
>> + struct aio_kiocb *kiocb)
>> +{
>> + if (!state || !IS_ENABLED(CONFIG_BLOCK))
>> + aio_iopoll_iocb_add_list(kiocb);
>
> This still looks odd to me. Why would be make a batch or not batch
> decision based on CONFIG_BLOCK availability? Either batching is safe
> for all ops, in which case we should always enabled it, or it only makes
> sense for block devices / block backed filesystem in which case we need
> a per-operation check.
It is safe for any device, but ideally we want the schedule flush to
be enabled to not sit on requests if we block.
The alternative is to make the plug cb handling available with
!CONFIG_BLOCK and not need these checks.
--
Jens Axboe
next prev parent reply other threads:[~2018-12-27 20:31 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-21 19:22 [PATCHSET v10] Support for polled and buffered aio (and more) Jens Axboe
2018-12-21 19:22 ` [PATCH 01/22] fs: add an iopoll method to struct file_operations Jens Axboe
2018-12-21 19:22 ` [PATCH 02/22] block: add bio_set_polled() helper Jens Axboe
2018-12-21 19:22 ` [PATCH 03/22] block: wire up block device iopoll method Jens Axboe
2018-12-21 19:22 ` [PATCH 04/22] block: use REQ_HIPRI_ASYNC for non-sync polled IO Jens Axboe
2018-12-21 19:25 ` Jens Axboe
2018-12-27 13:15 ` Christoph Hellwig
2018-12-27 20:22 ` Jens Axboe
2018-12-21 19:22 ` [PATCH 05/22] block: use bio_set_polled() helper for O_DIRECT Jens Axboe
2018-12-21 19:22 ` [PATCH 06/22] iomap: wire up the iopoll method Jens Axboe
2018-12-21 19:22 ` [PATCH 07/22] aio: add io_setup2() system call Jens Axboe
2018-12-27 13:55 ` Christoph Hellwig
2018-12-27 20:27 ` Jens Axboe
2018-12-21 19:22 ` [PATCH 08/22] aio: support for IO polling Jens Axboe
2018-12-27 13:55 ` Christoph Hellwig
2018-12-27 20:29 ` Jens Axboe
2018-12-21 19:22 ` [PATCH 09/22] aio: add submission side request cache Jens Axboe
2018-12-27 13:56 ` Christoph Hellwig
2018-12-27 20:31 ` Jens Axboe [this message]
2018-12-21 19:22 ` [PATCH 10/22] fs: add fget_many() and fput_many() Jens Axboe
2018-12-21 19:22 ` [PATCH 11/22] aio: use fget/fput_many() for file references Jens Axboe
2018-12-21 19:22 ` [PATCH 12/22] aio: split iocb init from allocation Jens Axboe
2018-12-21 19:22 ` [PATCH 13/22] aio: batch aio_kiocb allocation Jens Axboe
2018-12-21 19:22 ` [PATCH 14/22] aio: split old ring complete out from aio_complete() Jens Axboe
2018-12-21 19:22 ` [PATCH 15/22] aio: pass in user index to __io_submit_one() Jens Axboe
2018-12-21 19:22 ` [PATCH 16/22] aio: add support for submission/completion rings Jens Axboe
2018-12-27 13:47 ` Christoph Hellwig
2019-01-02 16:28 ` Jens Axboe
2019-01-02 20:32 ` Jens Axboe
2019-01-02 19:11 ` Jeff Moyer
2018-12-21 19:22 ` [PATCH 17/22] block: implement bio helper to add iter bvec pages to bio Jens Axboe
2018-12-21 19:22 ` [PATCH 18/22] aio: add support for pre-mapped user IO buffers Jens Axboe
2018-12-27 13:57 ` Christoph Hellwig
2018-12-21 19:22 ` [PATCH 19/22] aio: support kernel side submission for aio with SCQRING Jens Axboe
2018-12-27 13:57 ` Christoph Hellwig
2018-12-27 20:34 ` Jens Axboe
2018-12-21 19:22 ` [PATCH 20/22] aio: enable polling for IOCTX_FLAG_SQTHREAD Jens Axboe
2018-12-21 19:22 ` [PATCH 21/22] aio: utilize io_event->res2 for CQ ring Jens Axboe
2018-12-21 19:22 ` [PATCH 22/22] aio: add my copyright Jens Axboe
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