From: Dan Williams <dan.j.williams@intel.com>
To: 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>,
Vishal Verma <vishal.l.verma@intel.com>,
Dave Jiang <dave.jiang@intel.com>,
Ira Weiny <ira.weiny@intel.com>,
Matthew Wilcox <willy@infradead.org>, 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 Mailing List <linux-kernel@vger.kernel.org>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
linux-nvdimm <linux-nvdimm@lists.01.org>
Subject: Re: [PATCH] pmem: export the symbols __copy_user_flushcache and __copy_from_user_flushcache
Date: Wed, 16 Sep 2020 10:40:13 -0700 [thread overview]
Message-ID: <CAPcyv4gD0ZFkfajKTDnJhEEjf+5Av-GH+cHRFoyhzGe8bNEgAA@mail.gmail.com> (raw)
In-Reply-To: <alpine.LRH.2.02.2009161254400.745@file01.intranet.prod.int.rdu2.redhat.com>
On Wed, Sep 16, 2020 at 10:24 AM Mikulas Patocka <mpatocka@redhat.com> wrote:
>
>
>
> On Wed, 16 Sep 2020, Dan Williams wrote:
>
> > On Wed, Sep 16, 2020 at 3:57 AM Mikulas Patocka <mpatocka@redhat.com> wrote:
> > >
> > >
> > >
> > > I'm submitting this patch that adds the required exports (so that we could
> > > use __copy_from_user_flushcache on x86, arm64 and powerpc). Please, queue
> > > it for the next merge window.
> >
> > Why? This should go with the first user, and it's not clear that it
> > needs to be relative to the current dax_operations export scheme.
>
> Before nvfs gets included in the kernel, I need to distribute it as a
> module. So, it would make my maintenance easier. But if you don't want to
> export it now, no problem, I can just copy __copy_user_flushcache from the
> kernel to the module.
That sounds a better plan than exporting symbols with no in-kernel consumer.
> > My first question about nvfs is how it compares to a daxfs with
> > executables and other binaries configured to use page cache with the
> > new per-file dax facility?
>
> nvfs is faster than dax-based filesystems on metadata-heavy operations
> because it doesn't have the overhead of the buffer cache and bios. See
> this: http://people.redhat.com/~mpatocka/nvfs/BENCHMARKS
...and that metadata problem is intractable upstream? Christoph poked
at bypassing the block layer for xfs metadata operations [1], I just
have not had time to carry that further.
[1]: "xfs: use dax_direct_access for log writes", although it seems
he's dropped that branch from his xfs.git
next prev parent reply other threads:[~2020-09-16 17:42 UTC|newest]
Thread overview: 38+ 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 13:00 ` Matthew Wilcox
2020-09-15 13:24 ` Mikulas Patocka
2020-09-22 10:04 ` Ritesh Harjani
2020-09-15 15:16 ` Dan Williams
2020-09-15 16:58 ` 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 16:21 ` Dan Williams
2020-09-16 17:24 ` Mikulas Patocka
2020-09-16 17:40 ` Dan Williams [this message]
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
2020-09-22 5:03 ` Dave Chinner
2020-09-22 16:46 ` Mikulas Patocka
2020-09-22 17:25 ` Matthew Wilcox
2020-09-24 15:00 ` Mikulas Patocka
2020-09-28 15:22 ` Mikulas Patocka
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 17:19 ` NVFS XFS metadata (was: [PATCH] pmem: export the symbols __copy_user_flushcache and __copy_from_user_flushcache) Mikulas Patocka
2020-09-23 9:57 ` Jan Kara
2020-09-23 13:11 ` Mikulas Patocka
2020-09-23 15:04 ` Matthew Wilcox
2020-09-22 12:28 ` Matthew Wilcox
2020-09-22 12:39 ` Mikulas Patocka
2020-09-16 18:56 ` [PATCH] pmem: fix __copy_user_flushcache Mikulas Patocka
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
2020-09-21 16:19 ` [RFC] nvfs: a filesystem for persistent memory Mikulas Patocka
2020-09-21 16:29 ` Dan Williams
2020-09-22 15:43 ` Ira Weiny
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