From: Jens Axboe <axboe@kernel.dk>
To: linux-fsdevel@vger.kernel.org, linux-aio@kvack.org
Cc: hch@lst.de, viro@zeniv.linux.org.uk, Jens Axboe <axboe@kernel.dk>
Subject: [PATCH 02/22] block: add REQ_HIPRI_ASYNC
Date: Tue, 18 Dec 2018 08:42:10 -0700 [thread overview]
Message-ID: <20181218154230.3120-3-axboe@kernel.dk> (raw)
In-Reply-To: <20181218154230.3120-1-axboe@kernel.dk>
For the upcoming async polled IO, we can't sleep allocating requests.
If we do, then we introduce a deadlock where the submitter already
has async polled IO in-flight, but can't wait for them to complete
since polled requests must be active found and reaped.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
include/linux/blk_types.h | 1 +
1 file changed, 1 insertion(+)
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index fc99474ac968..4845250b5ba0 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -348,6 +348,7 @@ enum req_flag_bits {
#define REQ_NOWAIT (1ULL << __REQ_NOWAIT)
#define REQ_NOUNMAP (1ULL << __REQ_NOUNMAP)
#define REQ_HIPRI (1ULL << __REQ_HIPRI)
+#define REQ_HIPRI_ASYNC (REQ_HIPRI | REQ_NOWAIT)
#define REQ_DRV (1ULL << __REQ_DRV)
#define REQ_SWAP (1ULL << __REQ_SWAP)
--
2.17.1
next prev parent reply other threads:[~2018-12-18 15:42 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-18 15:42 [PATCHSET v9] Support for polled and buffered aio (and more) Jens Axboe
2018-12-18 15:42 ` [PATCH 01/22] fs: add an iopoll method to struct file_operations Jens Axboe
2018-12-18 15:42 ` Jens Axboe [this message]
2018-12-21 11:20 ` [PATCH 02/22] block: add REQ_HIPRI_ASYNC Christoph Hellwig
2018-12-21 14:33 ` Jens Axboe
2018-12-18 15:42 ` [PATCH 03/22] block: wire up block device iopoll method Jens Axboe
2018-12-18 15:42 ` [PATCH 04/22] block: use REQ_HIPRI_ASYNC for non-sync polled IO Jens Axboe
2018-12-18 15:42 ` [PATCH 05/22] iomap: wire up the iopoll method Jens Axboe
2018-12-18 15:42 ` [PATCH 06/22] aio: add io_setup2() system call Jens Axboe
2018-12-21 11:21 ` Christoph Hellwig
2018-12-18 15:42 ` [PATCH 07/22] aio: support for IO polling Jens Axboe
2018-12-21 11:25 ` Christoph Hellwig
2018-12-21 14:28 ` Jens Axboe
2018-12-18 15:42 ` [PATCH 08/22] aio: add submission side request cache Jens Axboe
2018-12-21 11:28 ` Christoph Hellwig
2018-12-21 15:37 ` Jens Axboe
2018-12-21 15:42 ` Jens Axboe
2018-12-18 15:42 ` [PATCH 09/22] fs: add fget_many() and fput_many() Jens Axboe
2018-12-18 15:42 ` [PATCH 10/22] aio: use fget/fput_many() for file references Jens Axboe
2018-12-18 15:42 ` [PATCH 11/22] aio: split iocb init from allocation Jens Axboe
2018-12-18 15:42 ` [PATCH 12/22] aio: batch aio_kiocb allocation Jens Axboe
2018-12-18 15:42 ` [PATCH 13/22] aio: split old ring complete out from aio_complete() Jens Axboe
2018-12-18 15:42 ` [PATCH 14/22] aio: pass in user index to __io_submit_one() Jens Axboe
2018-12-18 15:42 ` [PATCH 15/22] aio: add support for submission/completion rings Jens Axboe
2018-12-18 15:42 ` [PATCH 16/22] block: add BIO_HOLD_PAGES flag Jens Axboe
2018-12-21 11:30 ` Christoph Hellwig
2018-12-21 14:22 ` Jens Axboe
2018-12-18 15:42 ` [PATCH 17/22] block: implement bio helper to add iter bvec pages to bio Jens Axboe
2018-12-21 11:32 ` Christoph Hellwig
2018-12-21 14:21 ` Jens Axboe
2018-12-18 15:42 ` [PATCH 18/22] aio: add support for pre-mapped user IO buffers Jens Axboe
2018-12-18 15:42 ` [PATCH 19/22] aio: support kernel side submission for aio with SCQRING Jens Axboe
2018-12-18 15:42 ` [PATCH 20/22] aio: enable polling for IOCTX_FLAG_SQTHREAD Jens Axboe
2018-12-18 15:42 ` [PATCH 21/22] aio: utilize io_event->res2 for CQ ring Jens Axboe
2018-12-18 15:42 ` [PATCH 22/22] aio: add my copyright Jens Axboe
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