From: Ritesh Harjani <riteshh@linux.ibm.com>
To: Matthew Wilcox <willy@infradead.org>,
Mikulas Patocka <mpatocka@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Andrew Morton <akpm@linux-foundation.org>,
Jan Kara <jack@suse.cz>, Eric Sandeen <esandeen@redhat.com>,
Dave Chinner <dchinner@redhat.com>,
"Tadakamadla,
Rajesh (DCIG/CDI/HPS Perf)" <rajesh.tadakamadla@hpe.com>,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-nvdimm@lists.01.org
Subject: Re: [RFC] nvfs: a filesystem for persistent memory
Date: Tue, 22 Sep 2020 15:34:37 +0530 [thread overview]
Message-ID: <20d31308-e60a-99f2-3309-c9f6c115e32b@linux.ibm.com> (raw)
In-Reply-To: <20200915130012.GC5449@casper.infradead.org>
On 9/15/20 6:30 PM, Matthew Wilcox wrote:
> On Tue, Sep 15, 2020 at 08:34:41AM -0400, Mikulas Patocka wrote:
>> - when the fsck.nvfs tool mmaps the device /dev/pmem0, the kernel uses
>> buffer cache for the mapping. The buffer cache slows does fsck by a factor
>> of 5 to 10. Could it be possible to change the kernel so that it maps DAX
>> based block devices directly?
>
> Oh, because fs/block_dev.c has:
> .mmap = generic_file_mmap,
>
> I don't see why we shouldn't have a blkdev_mmap modelled after
> ext2_file_mmap() with the corresponding blkdev_dax_vm_ops.
>
pls help with below 2 queries:-
1. Can't we use ->direct_IO here to avoid the mentioned performance problem?
2. Any other existing use case where having this blkdev_dax_vm_ops be
useful?
-ritesh
_______________________________________________
Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org
To unsubscribe send an email to linux-nvdimm-leave@lists.01.org
WARNING: multiple messages have this Message-ID (diff)
From: Ritesh Harjani <riteshh@linux.ibm.com>
To: Matthew Wilcox <willy@infradead.org>,
Mikulas Patocka <mpatocka@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Andrew Morton <akpm@linux-foundation.org>,
Dan Williams <dan.j.williams@intel.com>,
Vishal Verma <vishal.l.verma@intel.com>,
Dave Jiang <dave.jiang@intel.com>,
Ira Weiny <ira.weiny@intel.com>, Jan Kara <jack@suse.cz>,
Eric Sandeen <esandeen@redhat.com>,
Dave Chinner <dchinner@redhat.com>,
"Kani, Toshi" <toshi.kani@hpe.com>,
"Norton, Scott J" <scott.norton@hpe.com>,
"Tadakamadla,
Rajesh (DCIG/CDI/HPS Perf)" <rajesh.tadakamadla@hpe.com>,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-nvdimm@lists.01.org
Subject: Re: [RFC] nvfs: a filesystem for persistent memory
Date: Tue, 22 Sep 2020 15:34:37 +0530 [thread overview]
Message-ID: <20d31308-e60a-99f2-3309-c9f6c115e32b@linux.ibm.com> (raw)
In-Reply-To: <20200915130012.GC5449@casper.infradead.org>
On 9/15/20 6:30 PM, Matthew Wilcox wrote:
> On Tue, Sep 15, 2020 at 08:34:41AM -0400, Mikulas Patocka wrote:
>> - when the fsck.nvfs tool mmaps the device /dev/pmem0, the kernel uses
>> buffer cache for the mapping. The buffer cache slows does fsck by a factor
>> of 5 to 10. Could it be possible to change the kernel so that it maps DAX
>> based block devices directly?
>
> Oh, because fs/block_dev.c has:
> .mmap = generic_file_mmap,
>
> I don't see why we shouldn't have a blkdev_mmap modelled after
> ext2_file_mmap() with the corresponding blkdev_dax_vm_ops.
>
pls help with below 2 queries:-
1. Can't we use ->direct_IO here to avoid the mentioned performance problem?
2. Any other existing use case where having this blkdev_dax_vm_ops be
useful?
-ritesh
next prev parent reply other threads:[~2020-09-22 10:05 UTC|newest]
Thread overview: 70+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-15 12:34 [RFC] nvfs: a filesystem for persistent memory Mikulas Patocka
2020-09-15 12:34 ` Mikulas Patocka
2020-09-15 13:00 ` Matthew Wilcox
2020-09-15 13:00 ` Matthew Wilcox
2020-09-15 13:24 ` Mikulas Patocka
2020-09-15 13:24 ` Mikulas Patocka
2020-09-22 10:04 ` Ritesh Harjani [this message]
2020-09-22 10:04 ` Ritesh Harjani
2020-09-15 15:16 ` Dan Williams
2020-09-15 15:16 ` Dan Williams
2020-09-15 16:58 ` Mikulas Patocka
2020-09-15 16:58 ` Mikulas Patocka
2020-09-15 17:38 ` Mikulas Patocka
2020-09-15 17:38 ` Mikulas Patocka
2020-09-16 10:57 ` [PATCH] pmem: export the symbols __copy_user_flushcache and __copy_from_user_flushcache Mikulas Patocka
2020-09-16 10:57 ` Mikulas Patocka
2020-09-16 16:21 ` Dan Williams
2020-09-16 16:21 ` Dan Williams
2020-09-16 17:24 ` Mikulas Patocka
2020-09-16 17:24 ` Mikulas Patocka
2020-09-16 17:40 ` Dan Williams
2020-09-16 17:40 ` Dan Williams
2020-09-16 18:06 ` Mikulas Patocka
2020-09-16 18:06 ` Mikulas Patocka
2020-09-21 16:20 ` NVFS XFS metadata (was: [PATCH] pmem: export the symbols __copy_user_flushcache and __copy_from_user_flushcache) Mikulas Patocka
2020-09-21 16:20 ` Mikulas Patocka
2020-09-22 5:03 ` Dave Chinner
2020-09-22 5:03 ` Dave Chinner
2020-09-22 16:46 ` Mikulas Patocka
2020-09-22 16:46 ` Mikulas Patocka
2020-09-22 17:25 ` Matthew Wilcox
2020-09-22 17:25 ` Matthew Wilcox
2020-09-24 15:00 ` Mikulas Patocka
2020-09-24 15:00 ` Mikulas Patocka
2020-09-28 15:22 ` Mikulas Patocka
2020-09-28 15:22 ` Mikulas Patocka
2020-09-23 2:45 ` Dave Chinner
2020-09-23 2:45 ` Dave Chinner
2020-09-23 9:20 ` A bug in ext4 with big directories (was: NVFS XFS metadata) Mikulas Patocka
2020-09-23 9:44 ` Jan Kara
2020-09-23 12:46 ` Mikulas Patocka
2020-09-23 20:20 ` Andreas Dilger
2020-09-23 17:19 ` NVFS XFS metadata (was: [PATCH] pmem: export the symbols __copy_user_flushcache and __copy_from_user_flushcache) Mikulas Patocka
2020-09-23 17:19 ` Mikulas Patocka
2020-09-23 9:57 ` Jan Kara
2020-09-23 9:57 ` Jan Kara
2020-09-23 13:11 ` Mikulas Patocka
2020-09-23 13:11 ` Mikulas Patocka
2020-09-23 15:04 ` Matthew Wilcox
2020-09-23 15:04 ` Matthew Wilcox
2020-09-22 12:28 ` Matthew Wilcox
2020-09-22 12:28 ` Matthew Wilcox
2020-09-22 12:39 ` Mikulas Patocka
2020-09-22 12:39 ` Mikulas Patocka
2020-09-16 18:56 ` [PATCH] pmem: fix __copy_user_flushcache Mikulas Patocka
2020-09-16 18:56 ` Mikulas Patocka
2020-09-18 1:53 ` Dan Williams
2020-09-18 1:53 ` Dan Williams
2020-09-18 12:25 ` the "read" syscall sees partial effects of the "write" syscall Mikulas Patocka
2020-09-18 13:13 ` Jan Kara
2020-09-18 18:02 ` Linus Torvalds
2020-09-20 23:41 ` Dave Chinner
2020-09-17 6:50 ` [PATCH] pmem: export the symbols __copy_user_flushcache and __copy_from_user_flushcache Christoph Hellwig
2020-09-17 6:50 ` Christoph Hellwig
2020-09-21 16:19 ` [RFC] nvfs: a filesystem for persistent memory Mikulas Patocka
2020-09-21 16:19 ` Mikulas Patocka
2020-09-21 16:29 ` Dan Williams
2020-09-21 16:29 ` Dan Williams
2020-09-22 15:43 ` Ira Weiny
2020-09-22 15:43 ` Ira Weiny
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20d31308-e60a-99f2-3309-c9f6c115e32b@linux.ibm.com \
--to=riteshh@linux.ibm.com \
--cc=akpm@linux-foundation.org \
--cc=dchinner@redhat.com \
--cc=esandeen@redhat.com \
--cc=jack@suse.cz \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-nvdimm@lists.01.org \
--cc=mpatocka@redhat.com \
--cc=rajesh.tadakamadla@hpe.com \
--cc=torvalds@linux-foundation.org \
--cc=viro@zeniv.linux.org.uk \
--cc=willy@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.