From: Jens Axboe <axboe@kernel.dk>
To: Jeff Moyer <jmoyer@redhat.com>
Cc: linux-fsdevel@vger.kernel.org, linux-aio@kvack.org,
linux-block@vger.kernel.org, hch@lst.de, avi@scylladb.com
Subject: Re: [PATCH 09/13] io_uring: add submission polling
Date: Mon, 28 Jan 2019 14:28:46 -0700 [thread overview]
Message-ID: <1fc20715-bdc6-6c36-7a53-58c91458db2b@kernel.dk> (raw)
In-Reply-To: <x49r2cwwkno.fsf@segfault.boston.devel.redhat.com>
On 1/28/19 2:13 PM, Jeff Moyer wrote:
> Jens Axboe <axboe@kernel.dk> writes:
>
>> @@ -1270,6 +1445,27 @@ static int io_sq_offload_start(struct io_ring_ctx *ctx)
>> if (!ctx->sqo_files)
>> goto err;
>>
>> + if (ctx->flags & IORING_SETUP_SQPOLL) {
>> + if (p->flags & IORING_SETUP_SQ_AFF) {
>> + ctx->sqo_thread = kthread_create_on_cpu(io_sq_thread,
>> + ctx, p->sq_thread_cpu,
>> + "io_uring-sq");
>
> sq_thread_cpu looks like another candidate for array_index_nospec.
> Following the macros, kthread_create_on_cpu calls cpu_to_node, which
> does:
> return per_cpu(x86_cpu_to_node_map, cpu);
>
> #define per_cpu(var, cpu) (*per_cpu_ptr(&(var), cpu))
> #define per_cpu_ptr(ptr, cpu) \
> ({ \
> __verify_pcpu_ptr(ptr); \
> SHIFT_PERCPU_PTR((ptr), per_cpu_offset((cpu))); \
> })
> #define per_cpu_offset(x) (__per_cpu_offset[x])
> ^^^^^^^^^^^^^^^^^^^
>
> It also looks like there's no bounds checking there, so we probably want
> to make sure sq_thread_cpu can't overflow the __per_cpu_offset array
> (NR_CPUS).
Added, can't hurt in any case.
--
Jens Axboe
next prev parent reply other threads:[~2019-01-28 21:28 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-23 15:35 [PATCHSET v7] io_uring IO interface Jens Axboe
2019-01-23 15:35 ` [PATCH 01/18] fs: add an iopoll method to struct file_operations Jens Axboe
2019-01-28 14:25 ` Christoph Hellwig
2019-01-28 16:13 ` Jens Axboe
2019-01-23 15:35 ` [PATCH 02/18] block: wire up block device iopoll method Jens Axboe
2019-01-23 15:35 ` [PATCH 03/18] block: add bio_set_polled() helper Jens Axboe
2019-01-28 14:26 ` Christoph Hellwig
2019-01-23 15:35 ` [PATCH 04/18] iomap: wire up the iopoll method Jens Axboe
2019-01-23 15:35 ` [PATCH 05/18] Add io_uring IO interface Jens Axboe
2019-01-28 14:57 ` Christoph Hellwig
2019-01-28 16:26 ` Jens Axboe
2019-01-28 16:34 ` Christoph Hellwig
2019-01-28 19:32 ` Jens Axboe
2019-01-28 18:25 ` Jens Axboe
2019-01-29 6:30 ` Christoph Hellwig
2019-01-29 11:58 ` Arnd Bergmann
2019-01-29 15:20 ` Jens Axboe
2019-01-29 16:18 ` Arnd Bergmann
2019-01-29 16:19 ` Jens Axboe
2019-01-29 16:26 ` Arnd Bergmann
2019-01-29 16:28 ` Jens Axboe
2019-01-29 16:46 ` Arnd Bergmann
2019-01-29 0:47 ` Andy Lutomirski
2019-01-29 1:20 ` Jens Axboe
2019-01-29 6:45 ` Christoph Hellwig
2019-01-29 12:05 ` Arnd Bergmann
2019-01-31 5:11 ` Andy Lutomirski
2019-01-31 16:37 ` Jens Axboe
2019-01-23 15:35 ` [PATCH 06/18] io_uring: add fsync support Jens Axboe
2019-01-23 15:35 ` [PATCH 07/13] io_uring: add support for pre-mapped user IO buffers Jens Axboe
2019-01-23 15:35 ` [PATCH 07/18] io_uring: support for IO polling Jens Axboe
2019-01-28 15:02 ` Christoph Hellwig
2019-01-28 16:46 ` Jens Axboe
2019-01-29 6:27 ` Christoph Hellwig
2019-01-29 13:20 ` Jens Axboe
2019-01-23 15:35 ` [PATCH 08/18] fs: add fget_many() and fput_many() Jens Axboe
2019-01-28 14:29 ` Christoph Hellwig
2019-01-28 16:48 ` Jens Axboe
2019-01-23 15:35 ` [PATCH 08/13] io_uring: add file set registration Jens Axboe
2019-01-23 15:35 ` [PATCH 09/13] io_uring: add submission polling Jens Axboe
2019-01-28 15:09 ` Christoph Hellwig
2019-01-28 17:05 ` Jens Axboe
2019-01-29 6:29 ` Christoph Hellwig
2019-01-29 13:21 ` Jens Axboe
2019-01-28 21:13 ` Jeff Moyer
2019-01-28 21:28 ` Jens Axboe [this message]
2019-01-23 15:35 ` [PATCH 09/18] io_uring: use fget/fput_many() for file references Jens Axboe
2019-01-23 15:35 ` [PATCH 10/13] io_uring: add io_kiocb ref count Jens Axboe
2019-01-23 15:35 ` [PATCH 10/18] io_uring: batch io_kiocb allocation Jens Axboe
2019-01-23 15:35 ` [PATCH 11/18] block: implement bio helper to add iter bvec pages to bio Jens Axboe
2019-01-28 14:31 ` Christoph Hellwig
2019-01-28 16:54 ` Jens Axboe
2019-01-23 15:35 ` [PATCH 11/13] io_uring: add support for IORING_OP_POLL Jens Axboe
2019-01-23 15:35 ` [PATCH 12/18] io_uring: add support for pre-mapped user IO buffers Jens Axboe
2019-01-23 15:35 ` [PATCH 12/13] io_uring: allow workqueue item to handle multiple buffered requests Jens Axboe
2019-01-23 15:35 ` [PATCH 13/18] io_uring: add file set registration Jens Axboe
2019-01-23 15:35 ` [PATCH 13/13] io_uring: add io_uring_event cache hit information Jens Axboe
2019-01-23 15:35 ` [PATCH 14/18] io_uring: add submission polling Jens Axboe
2019-01-23 15:35 ` [PATCH 15/18] io_uring: add io_kiocb ref count Jens Axboe
2019-01-23 15:35 ` [PATCH 16/18] io_uring: add support for IORING_OP_POLL Jens Axboe
2019-01-23 15:35 ` [PATCH 17/18] io_uring: allow workqueue item to handle multiple buffered requests Jens Axboe
2019-01-23 15:35 ` [PATCH 18/18] io_uring: add io_uring_event cache hit information Jens Axboe
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