From: Sergei Shtepa <sergei.shtepa@veeam.com>
To: Hillf Danton <hdanton@sina.com>
Cc: "axboe@kernel.dk" <axboe@kernel.dk>,
"corbet@lwn.net" <corbet@lwn.net>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 17/21] block, blksnap: snapshot image block device
Date: Mon, 2 Jan 2023 10:44:06 +0100 [thread overview]
Message-ID: <b2ec41dd-3346-c2db-d59c-9050f8ad1053@veeam.com> (raw)
In-Reply-To: <20230101071813.3329-1-hdanton@sina.com>
On 1/1/23 08:18, Hillf Danton wrote:
> Subject:
> Re: [PATCH v2 17/21] block, blksnap: snapshot image block device
> From:
> Hillf Danton <hdanton@sina.com>
> Date:
> 1/1/23, 08:18
>
> To:
> Sergei Shtepa <sergei.shtepa@veeam.com>
> CC:
> "axboe@kernel.dk" <axboe@kernel.dk>, "corbet@lwn.net" <corbet@lwn.net>, "linux-mm@kvack.org" <linux-mm@kvack.org>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
>
>
> This is the first time you've received an email from this sender
> hdanton@sina.com, please exercise caution when clicking on links or opening
> attachments.
>
>
> On 9 Dec 2022 15:23:27 +0100 Sergei Shtepa
> > Provides the operation of block devices of snapshot images. Read and
> > write operations are redirected to the regions of difference blocks for
> > block device (struct diff_area).
> >
> > Signed-off-by: Sergei Shtepa
> > ---
>
> Thanks for your patchset.
Thanks for the review.
>
> > +static int snapimage_kthread_worker_fn(void *param)
> > +{
> > + struct snapimage *snapimage = param;
> > + struct bio *bio;
> > + int ret = 0;
> > +
> > + while (!kthread_should_stop()) {
> > + bio = get_bio_from_queue(snapimage);
> > + if (!bio) {
> > + schedule_timeout_interruptible(HZ / 100);
> > + continue;
> > + }
>
> Given the wake_up_process() below, s$HZ / 100$HZ * 1000$ to avoid
> unnecessary wakeups [1].
>
> And because of no signal handling added, use schedule_timeout_idle() instead.
Yes, this function will be rewritten to eliminate unnecessary wake-ups.
The code that Christoph proposed in the letter at Dec 15 should work well.
>
> [1]
> https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore.kernel.org%2Flkml%2F20210419085027.761150-2-elver%40google.com%2F&data=05%7C01%7Csergei.shtepa%40veeam.com%7C765d591d47ad4d93857208daebc92508%7Cba07baab431b49edadd7cbc3542f5140%7C1%7C1%7C638081546440884849%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=rbINOq7m31DFhjHLnQKFHQuoWB64ZhmnWbAVLuNwv7w%3D&reserved=0
>
> > +
> > + snapimage_process_bio(snapimage, bio);
> > + }
> > +
> > + while ((bio = get_bio_from_queue(snapimage)))
> > + snapimage_process_bio(snapimage, bio);
> > +
> > + return ret;
> > +}
> > +
> > +static void snapimage_submit_bio(struct bio *bio)
> > +{
> > + struct snapimage *snapimage = bio->bi_bdev->bd_disk->private_data;
> > + gfp_t gfp = GFP_NOIO;
> > +
> > + if (bio->bi_opf & REQ_NOWAIT)
> > + gfp |= GFP_NOWAIT;
> > + if (snapimage->is_ready) {
> > + spin_lock(&snapimage->queue_lock);
> > + bio_list_add(&snapimage->queue, bio);
> > + spin_unlock(&snapimage->queue_lock);
> > +
> > + wake_up_process(snapimage->worker);
> > + } else
> > + bio_io_error(bio);
> > +}
>
next prev parent reply other threads:[~2023-01-02 9:45 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-09 14:23 [PATCH v2 00/21] blksnap - block devices snapshots module Sergei Shtepa
2022-12-09 14:23 ` [PATCH v2 01/21] documentation, blkfilter: Block Device Filtering Mechanism Sergei Shtepa
2022-12-10 4:15 ` Bagas Sanjaya
2022-12-09 14:23 ` [PATCH v2 02/21] block, " Sergei Shtepa
2022-12-15 9:26 ` Christoph Hellwig
2022-12-15 10:46 ` Sergei Shtepa
2022-12-16 7:04 ` Christoph Hellwig
2023-01-31 23:58 ` Mike Snitzer
2023-02-01 11:09 ` Fabio Fantoni
2023-02-01 13:16 ` Sergei Shtepa
2022-12-09 14:23 ` [PATCH v2 03/21] documentation, capability: fix Generic Block Device Capability Sergei Shtepa
2022-12-13 12:13 ` Fabio Fantoni
2022-12-30 15:35 ` Fabio Fantoni
2022-12-09 14:23 ` [PATCH v2 04/21] documentation, blksnap: Block Devices Snapshots Module Sergei Shtepa
2022-12-10 3:50 ` Bagas Sanjaya
2022-12-09 14:23 ` [PATCH v2 05/21] block, blksnap: header file of the module interface Sergei Shtepa
2022-12-09 22:13 ` kernel test robot
2022-12-09 23:14 ` kernel test robot
2022-12-09 14:23 ` [PATCH v2 06/21] block, blksnap: module management interface functions Sergei Shtepa
2022-12-15 9:28 ` Christoph Hellwig
[not found] ` <CGME20230103153406eucas1p205c48bd767e6a86f6f1121db7eb5fc19@eucas1p2.samsung.com>
2023-01-03 15:26 ` Pankaj Raghav
2022-12-09 14:23 ` [PATCH v2 07/21] block, blksnap: init() and exit() functions Sergei Shtepa
2022-12-15 9:30 ` Christoph Hellwig
2022-12-09 14:23 ` [PATCH v2 08/21] block, blksnap: interaction with sysfs Sergei Shtepa
2022-12-09 14:23 ` [PATCH v2 09/21] block, blksnap: attaching and detaching the filter and handling I/O units Sergei Shtepa
2022-12-15 10:01 ` Christoph Hellwig
2022-12-09 14:23 ` [PATCH v2 10/21] block, blksnap: map of change block tracking Sergei Shtepa
2022-12-09 14:23 ` [PATCH v2 11/21] block, blksnap: minimum data storage unit of the original block device Sergei Shtepa
2022-12-09 14:23 ` [PATCH v2 12/21] block, blksnap: buffer in memory for the minimum data storage unit Sergei Shtepa
2022-12-09 14:23 ` [PATCH v2 13/21] block, blksnap: functions and structures for performing block I/O operations Sergei Shtepa
2022-12-15 10:06 ` Christoph Hellwig
2022-12-09 14:23 ` [PATCH v2 14/21] block, blksnap: storage for storing difference blocks Sergei Shtepa
2022-12-09 14:23 ` [PATCH v2 15/21] block, blksnap: event queue from the difference storage Sergei Shtepa
2022-12-09 14:23 ` [PATCH v2 16/21] block, blksnap: owner of information about overwritten blocks of the original block device Sergei Shtepa
2022-12-09 14:23 ` [PATCH v2 17/21] block, blksnap: snapshot image " Sergei Shtepa
2022-12-15 9:45 ` Christoph Hellwig
2022-12-09 14:23 ` [PATCH v2 18/21] block, blksnap: snapshot Sergei Shtepa
2022-12-09 14:23 ` [PATCH v2 19/21] block, blksnap: Kconfig and Makefile Sergei Shtepa
2022-12-09 14:23 ` [PATCH v2 20/21] block, blksnap: adds a blksnap to the kernel tree Sergei Shtepa
2022-12-09 21:53 ` kernel test robot
2022-12-09 14:23 ` [PATCH v2 21/21] block, blksnap: adds a maintainer for new files Sergei Shtepa
2022-12-10 3:23 ` [PATCH v2 00/21] blksnap - block devices snapshots module Bagas Sanjaya
2022-12-10 22:57 ` Sergei Shtepa
[not found] ` <20230101071813.3329-1-hdanton@sina.com>
2023-01-02 9:44 ` Sergei Shtepa [this message]
[not found] ` <20230101110542.3395-1-hdanton@sina.com>
2023-01-02 9:58 ` [PATCH v2 18/21] block, blksnap: snapshot Sergei Shtepa
2023-01-17 21:04 ` [PATCH v2 00/21] blksnap - block devices snapshots module Mike Snitzer
2023-01-18 10:51 ` Hannes Reinecke
2023-01-24 11:34 ` Sergei Shtepa
2023-01-31 20:47 ` Mike Snitzer
2023-02-01 2:32 ` Mason Giles
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