From: "Martin K. Petersen" <martin.petersen@oracle.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: Hannes Reinecke <hare@suse.de>, Arnd Bergmann <arnd@arndb.de>,
"\(Exiting\) Baolin Wang" <baolin.wang@linaro.org>,
Baolin Wang <baolin.wang7@gmail.com>,
Adrian Hunter <adrian.hunter@intel.com>,
Ulf Hansson <ulf.hansson@linaro.org>,
asutoshd@codeaurora.org, Orson Zhai <orsonzhai@gmail.com>,
Lyra Zhang <zhang.lyra@gmail.com>,
Linus Walleij <linus.walleij@linaro.org>,
Vincent Guittot <vincent.guittot@linaro.org>,
linux-mmc <linux-mmc@vger.kernel.org>,
"linux-kernel\@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Hannes Reinecke <hare@suse.com>,
linux-block <linux-block@vger.kernel.org>,
Paolo Valente <paolo.valente@linaro.org>
Subject: Re: [PATCH v6 0/4] Add MMC software queue support
Date: Thu, 28 Nov 2019 07:15:09 -0500 [thread overview]
Message-ID: <yq1v9r46vua.fsf@oracle.com> (raw)
In-Reply-To: <20191127090023.GA23040@infradead.org> (Christoph Hellwig's message of "Wed, 27 Nov 2019 01:00:23 -0800")
Christoph,
> equivalent to SCSI logical units and nvme namespace, just with a
> pretty idiotic design decision that only allows I/O to one of them at
> a time. The block layer way to deal with them is to use a shared
> tagset for multiple request queues, which doesn't use up a whole lot
> of resources. The only hard part is the draining when switching
> between partitions, and there is no really nice way to deal with that.
> If requests are batched enough we could just drain and switch every
> time an other partition access comes in.
This mirrors single_lun in SCSI closely. I was hoping we could
eventually get rid of that travesty but if MMC needs something similar,
maybe it would be good to move that plumbing to block?
--
Martin K. Petersen Oracle Linux Engineering
WARNING: multiple messages have this Message-ID (diff)
From: "Martin K. Petersen" <martin.petersen@oracle.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: Hannes Reinecke <hare@suse.de>, Arnd Bergmann <arnd@arndb.de>,
"(Exiting) Baolin Wang" <baolin.wang@linaro.org>,
Baolin Wang <baolin.wang7@gmail.com>,
Adrian Hunter <adrian.hunter@intel.com>,
Ulf Hansson <ulf.hansson@linaro.org>,
asutoshd@codeaurora.org, Orson Zhai <orsonzhai@gmail.com>,
Lyra Zhang <zhang.lyra@gmail.com>,
Linus Walleij <linus.walleij@linaro.org>,
Vincent Guittot <vincent.guittot@linaro.org>,
linux-mmc <linux-mmc@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Hannes Reinecke <hare@suse.com>,
linux-block <linux-block@vger.kernel.org>,
Paolo Valente <paolo.valente@linaro.org>
Subject: Re: [PATCH v6 0/4] Add MMC software queue support
Date: Thu, 28 Nov 2019 07:15:09 -0500 [thread overview]
Message-ID: <yq1v9r46vua.fsf@oracle.com> (raw)
In-Reply-To: <20191127090023.GA23040@infradead.org> (Christoph Hellwig's message of "Wed, 27 Nov 2019 01:00:23 -0800")
Christoph,
> equivalent to SCSI logical units and nvme namespace, just with a
> pretty idiotic design decision that only allows I/O to one of them at
> a time. The block layer way to deal with them is to use a shared
> tagset for multiple request queues, which doesn't use up a whole lot
> of resources. The only hard part is the draining when switching
> between partitions, and there is no really nice way to deal with that.
> If requests are batched enough we could just drain and switch every
> time an other partition access comes in.
This mirrors single_lun in SCSI closely. I was hoping we could
eventually get rid of that travesty but if MMC needs something similar,
maybe it would be good to move that plumbing to block?
--
Martin K. Petersen Oracle Linux Engineering
next prev parent reply other threads:[~2019-11-28 12:17 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-11 7:33 [PATCH v6 0/4] Add MMC software queue support Baolin Wang
2019-11-11 7:33 ` [PATCH v6 1/4] mmc: Add MMC host " Baolin Wang
2019-11-11 7:33 ` Baolin Wang
2019-11-11 7:33 ` [PATCH v6 2/4] mmc: host: sdhci: Add request_done ops for struct sdhci_ops Baolin Wang
2019-11-11 7:33 ` [PATCH v6 3/4] mmc: host: sdhci-sprd: Add software queue support Baolin Wang
2019-11-11 7:34 ` [PATCH v6 4/4] mmc: host: sdhci: Add a variable to defer to complete requests if needed Baolin Wang
2019-11-11 7:44 ` Adrian Hunter
2019-11-11 7:57 ` Baolin Wang
2019-11-11 9:28 ` [PATCH v6 0/4] Add MMC software queue support Arnd Bergmann
2019-11-11 12:58 ` Baolin Wang
2019-11-11 16:59 ` Arnd Bergmann
2019-11-12 8:48 ` Baolin Wang
2019-11-18 10:04 ` (Exiting) Baolin Wang
2019-11-22 9:50 ` Arnd Bergmann
2019-11-22 13:19 ` Linus Walleij
2019-11-22 13:49 ` Arnd Bergmann
2019-11-26 7:40 ` Paolo Valente
2019-11-26 9:54 ` Arnd Bergmann
2019-11-26 11:17 ` Hannes Reinecke
2019-11-27 7:49 ` Baolin Wang
2019-11-27 9:00 ` Christoph Hellwig
2019-11-27 12:01 ` Arnd Bergmann
2019-12-10 15:17 ` Ulf Hansson
2019-11-28 12:15 ` Martin K. Petersen [this message]
2019-11-28 12:15 ` Martin K. Petersen
2019-11-28 15:54 ` Christoph Hellwig
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