Linux-Fsdevel Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Ira Weiny <ira.weiny@intel.com>
To: Mikulas Patocka <mpatocka@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>,
	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>,
	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: [RFC] nvfs: a filesystem for persistent memory
Date: Tue, 22 Sep 2020 08:43:59 -0700	[thread overview]
Message-ID: <20200922154359.GT2540965@iweiny-DESK2.sc.intel.com> (raw)
In-Reply-To: <alpine.LRH.2.02.2009211133190.15623@file01.intranet.prod.int.rdu2.redhat.com>

On Mon, Sep 21, 2020 at 12:19:07PM -0400, Mikulas Patocka wrote:
> 
> 
> On Tue, 15 Sep 2020, Dan Williams wrote:
> 
> > > TODO:
> > >
> > > - programs run approximately 4% slower when running from Optane-based
> > > persistent memory. Therefore, programs and libraries should use page cache
> > > and not DAX mapping.
> > 
> > This needs to be based on platform firmware data f(ACPI HMAT) for the
> > relative performance of a PMEM range vs DRAM. For example, this
> > tradeoff should not exist with battery backed DRAM, or virtio-pmem.
> 
> Hi
> 
> I have implemented this functionality - if we mmap a file with 
> (vma->vm_flags & VM_DENYWRITE), then it is assumed that this is executable 
> file mapping - the flag S_DAX on the inode is cleared on and the inode 
> will use normal page cache.
> 
> Is there some way how to test if we are using Optane-based module (where 
> this optimization should be applied) or battery backed DRAM (where it 
> should not)?
> 
> I've added mount options dax=never, dax=auto, dax=always, so that the user 
                                      ^^^^^^^^
				      dax=inode?

'inode' is the option used by ext4/xfs.

Ira

> can override the automatic behavior.
> 
> Mikulas
> 

      parent reply	other threads:[~2020-09-22 15:44 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-15 12:34 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
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 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  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 [this message]

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=20200922154359.GT2540965@iweiny-DESK2.sc.intel.com \
    --to=ira.weiny@intel.com \
    --cc=akpm@linux-foundation.org \
    --cc=dan.j.williams@intel.com \
    --cc=dave.jiang@intel.com \
    --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=scott.norton@hpe.com \
    --cc=torvalds@linux-foundation.org \
    --cc=toshi.kani@hpe.com \
    --cc=viro@zeniv.linux.org.uk \
    --cc=vishal.l.verma@intel.com \
    --cc=willy@infradead.org \
    --subject='Re: [RFC] nvfs: a filesystem for persistent memory' \
    /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

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).