From: Bart Van Assche <bvanassche@acm.org>
To: Can Guo <cang@codeaurora.org>, Avri Altman <Avri.Altman@wdc.com>
Cc: "James E . J . Bottomley" <jejb@linux.vnet.ibm.com>,
"Martin K . Petersen" <martin.petersen@oracle.com>,
"linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
yongmyung lee <ymhungry.lee@samsung.com>,
Daejun Park <daejun7.park@samsung.com>,
"alim.akhtar@samsung.com" <alim.akhtar@samsung.com>,
"asutoshd@codeaurora.org" <asutoshd@codeaurora.org>,
Zang Leigang <zangleigang@hisilicon.com>,
Avi Shchislowski <Avi.Shchislowski@wdc.com>,
Bean Huo <beanhuo@micron.com>,
"stanley.chu@mediatek.com" <stanley.chu@mediatek.com>
Subject: Re: [PATCH v5 07/10] scsi: ufshpb: Add "Cold" regions timer
Date: Tue, 1 Jun 2021 09:22:46 -0700 [thread overview]
Message-ID: <7953c9c3-d30c-496f-9fb3-15aa1a7e3e4a@acm.org> (raw)
In-Reply-To: <DM6PR04MB657542A19075691EC60BCEB7FC6A9@DM6PR04MB6575.namprd04.prod.outlook.com>
On 3/17/21 12:55 AM, Avri Altman wrote:
>> On 2021-03-16 17:21, Avri Altman wrote:
[ ... ]
>>>> And, which lock is protecting rgn->list_expired_rgn? If two
>>>> read_to_handler works
>>>> are running in parallel, one can be inserting it to its expired_list
>>>> while another
>>>> can be deleting it.
>>> The timeout handler, being a delayed work, is meant to run every
>>> polling period.
>>> Originally, I had it protected from 2 handlers running concurrently,
>>> But I removed it following Daejun's comment, which I accepted,
>>> Since it is always scheduled using the same polling period.
>>
>> But one can set the delay to 0 through sysfs, right?
>
> Will restore the protection. Thanks.
(replying to an email from 2.5 months ago)
Hi Can,
How can two read_to_handler works run in parallel? How can it make a
difference whether or not the delay can be set to zero? Are you aware
that since kernel v3.7 (released in 2012) all workqueues are
non-reentrant? See also commit dbf2576e37da ("workqueue: make all
workqueues non-reentrant"). From the description of that commit:
This patch makes all workqueues non-reentrant. If a work item is
executing on a different CPU when queueing is requested, it is
always queued to that CPU. This guarantees that any given work item
can be executing on one CPU at maximum and if a work item is queued
and executing, both are on the same CPU.
Thanks,
Bart.
next prev parent reply other threads:[~2021-06-01 16:22 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-02 13:24 [PATCH v5 00/10] Add Host control mode to HPB Avri Altman
2021-03-02 13:24 ` [PATCH v5 01/10] scsi: ufshpb: Cache HPB Control mode on init Avri Altman
2021-03-02 13:24 ` [PATCH v5 02/10] scsi: ufshpb: Add host control mode support to rsp_upiu Avri Altman
2021-03-02 13:24 ` [PATCH v5 03/10] scsi: ufshpb: Add region's reads counter Avri Altman
2021-03-11 7:52 ` Can Guo
2021-03-11 8:04 ` Avri Altman
2021-03-11 8:07 ` Can Guo
2021-03-15 3:16 ` Can Guo
2021-03-15 9:20 ` Avri Altman
2021-03-15 9:31 ` Can Guo
2021-03-17 9:19 ` Avri Altman
2021-03-15 8:40 ` Can Guo
2021-03-15 9:22 ` Avri Altman
2021-03-02 13:24 ` [PATCH v5 04/10] scsi: ufshpb: Make eviction depends on region's reads Avri Altman
2021-03-11 7:53 ` Can Guo
2021-03-11 8:06 ` Avri Altman
2021-03-15 8:30 ` Can Guo
2021-03-16 8:34 ` Avri Altman
2021-03-02 13:24 ` [PATCH v5 05/10] scsi: ufshpb: Region inactivation in host mode Avri Altman
2021-03-11 8:20 ` Can Guo
2021-03-11 9:03 ` Avri Altman
2021-03-15 4:02 ` Can Guo
2021-03-15 7:33 ` Can Guo
2021-03-16 8:30 ` Avri Altman
2021-03-17 1:23 ` Can Guo
[not found] ` <CGME20210316083014epcas2p32d6b84e689cdbe06ee065c870b236d65@epcms2p3>
2021-03-17 2:28 ` Daejun Park
2021-03-17 4:41 ` Can Guo
2021-03-17 7:59 ` Avri Altman
[not found] ` <CGME20210316083014epcas2p32d6b84e689cdbe06ee065c870b236d65@epcms2p4>
2021-03-17 5:19 ` Daejun Park
2021-03-17 5:34 ` Can Guo
[not found] ` <CGME20210316083014epcas2p32d6b84e689cdbe06ee065c870b236d65@epcms2p6>
2021-03-17 5:42 ` Daejun Park
2021-03-02 13:24 ` [PATCH v5 06/10] scsi: ufshpb: Add hpb dev reset response Avri Altman
2021-03-15 1:34 ` Can Guo
2021-03-15 6:40 ` Can Guo
2021-03-15 7:42 ` Avri Altman
2021-03-17 10:56 ` Can Guo
2021-03-17 11:23 ` Avri Altman
2021-03-17 12:12 ` Can Guo
2021-03-17 12:22 ` Avri Altman
2021-03-17 13:50 ` Can Guo
2021-03-17 14:22 ` Avri Altman
2021-03-17 14:36 ` Can Guo
2021-03-17 15:46 ` Avri Altman
2021-03-18 1:00 ` Can Guo
2021-03-18 8:04 ` Avri Altman
2021-03-02 13:25 ` [PATCH v5 07/10] scsi: ufshpb: Add "Cold" regions timer Avri Altman
2021-03-15 1:37 ` Can Guo
2021-03-15 7:54 ` Avri Altman
2021-03-15 9:36 ` Can Guo
2021-03-16 9:21 ` Avri Altman
2021-03-17 2:45 ` Can Guo
2021-03-17 7:55 ` Avri Altman
2021-06-01 16:22 ` Bart Van Assche [this message]
2021-03-02 13:25 ` [PATCH v5 08/10] scsi: ufshpb: Limit the number of inflight map requests Avri Altman
2021-03-15 8:31 ` Can Guo
2021-03-16 8:32 ` Avri Altman
2021-03-02 13:25 ` [PATCH v5 09/10] scsi: ufshpb: Add support for host control mode Avri Altman
2021-03-02 13:25 ` [PATCH v5 10/10] scsi: ufshpb: Make host mode parameters configurable Avri Altman
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