From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [PATCH 1/9] QUEUE_FLAG_NOWAIT to indicate device supports nowait To: Jens Axboe , Shaohua Li Cc: linux-block@vger.kernel.org, hch@infradead.org, jack@suse.cz, linux-raid@vger.kernel.org, dm-devel@redhat.com, Goldwyn Rodrigues References: <20170726235806.12148-1-rgoldwyn@suse.de> <20170726235806.12148-2-rgoldwyn@suse.de> <20170808203246.sdjnpzixxz5brjaf@kernel.org> <10dbe9f0-e2a0-456f-b271-7cf0312aa1d5@kernel.dk> <284fb7b3-9265-229f-4c66-bd043b94ec9f@kernel.dk> <0714ec15-9dad-f7a3-4f09-e7624f109de6@kernel.dk> From: Goldwyn Rodrigues Message-ID: Date: Thu, 10 Aug 2017 12:15:19 -0500 MIME-Version: 1.0 In-Reply-To: <0714ec15-9dad-f7a3-4f09-e7624f109de6@kernel.dk> Content-Type: text/plain; charset=utf-8 List-ID: On 08/10/2017 09:14 AM, Jens Axboe wrote: > On 08/10/2017 05:38 AM, Goldwyn Rodrigues wrote: >> >> >> On 08/09/2017 09:18 PM, Jens Axboe wrote: >>> On 08/08/2017 02:36 PM, Jens Axboe wrote: >>>> On 08/08/2017 02:32 PM, Shaohua Li wrote: >>>>>> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h >>>>>> index 25f6a0cb27d3..fae021ebec1b 100644 >>>>>> --- a/include/linux/blkdev.h >>>>>> +++ b/include/linux/blkdev.h >>>>>> @@ -633,6 +633,7 @@ struct request_queue { >>>>>> #define QUEUE_FLAG_REGISTERED 29 /* queue has been registered to a disk */ >>>>>> #define QUEUE_FLAG_SCSI_PASSTHROUGH 30 /* queue supports SCSI commands */ >>>>>> #define QUEUE_FLAG_QUIESCED 31 /* queue has been quiesced */ >>>>>> +#define QUEUE_FLAG_NOWAIT 32 /* stack device driver supports REQ_NOWAIT */ >>>> >>>> Does this work on 32-bit, where sizeof(unsigned long) == 32? >>> >>> I didn't get an answer to this one. >>> >> >> Oh, I assumed the question is rhetorical. >> No, it will not work on 32-bit. I was planning to change the field >> queue_flags to u64. Is that okay? > > No, besides that would not work with set/test_bit() and friends. Grab > a free bit instead. > Which bit is free? I don't see any gaps in QUEUE_FLAG_*, and I am not sure if any one is unused. -- Goldwyn