From: Christoph Hellwig <hch@lst.de>
To: Dan Williams <dan.j.williams@intel.com>
Cc: Linux NVDIMM <nvdimm@lists.linux.dev>,
linux-s390 <linux-s390@vger.kernel.org>,
Dave Jiang <dave.jiang@intel.com>,
Vasily Gorbik <gor@linux.ibm.com>,
Mike Snitzer <snitzer@redhat.com>,
Miklos Szeredi <miklos@szeredi.hu>,
Vishal Verma <vishal.l.verma@intel.com>,
Heiko Carstens <hca@linux.ibm.com>,
Matthew Wilcox <willy@infradead.org>,
virtualization@lists.linux-foundation.org,
Christian Borntraeger <borntraeger@de.ibm.com>,
device-mapper development <dm-devel@redhat.com>,
Vivek Goyal <vgoyal@redhat.com>,
Stefan Hajnoczi <stefanha@redhat.com>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
Ira Weiny <ira.weiny@intel.com>, Christoph Hellwig <hch@lst.de>,
Alasdair Kergon <agk@redhat.com>
Subject: Re: [dm-devel] [PATCH 4/5] dax: remove the copy_from_iter and copy_to_iter methods
Date: Mon, 13 Dec 2021 09:24:20 +0100 [thread overview]
Message-ID: <20211213082420.GC21462@lst.de> (raw)
In-Reply-To: <CAPcyv4gZjkVW0vwNLChXCCBVF8CsSZityzSVmcGAk79-mt9yOw@mail.gmail.com>
On Sun, Dec 12, 2021 at 06:39:16AM -0800, Dan Williams wrote:
> > /* flag to check if device supports synchronous flush */
> > DAXDEV_SYNC,
> > + /* do not use uncached operations to write data */
> > + DAXDEV_CACHED,
> > + /* do not use mcsafe operations to read data */
> > + DAXDEV_NOMCSAFE,
>
> Linus did not like the mcsafe name, and this brings it back. Let's
> flip the polarity to positively indicate which routine to use, and to
> match the 'nofault' style which says "copy and handle faults".
>
> /* do not leave the caches dirty after writes */
> DAXDEV_NOCACHE
>
> /* handle CPU fetch exceptions during reads */
> DAXDEV_NOMC
>
> ...and then flip the use cases around.
Sure we can do that. But let's finish the discussion if we actually
need the virtiofs special casing, as it seems pretty fishy in many
aspects.
--
dm-devel mailing list
dm-devel@redhat.com
https://listman.redhat.com/mailman/listinfo/dm-devel
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: Dan Williams <dan.j.williams@intel.com>
Cc: Christoph Hellwig <hch@lst.de>,
Vishal Verma <vishal.l.verma@intel.com>,
Dave Jiang <dave.jiang@intel.com>,
Alasdair Kergon <agk@redhat.com>,
Mike Snitzer <snitzer@redhat.com>,
Ira Weiny <ira.weiny@intel.com>,
Heiko Carstens <hca@linux.ibm.com>,
Vasily Gorbik <gor@linux.ibm.com>,
Christian Borntraeger <borntraeger@de.ibm.com>,
Vivek Goyal <vgoyal@redhat.com>,
Stefan Hajnoczi <stefanha@redhat.com>,
Miklos Szeredi <miklos@szeredi.hu>,
Matthew Wilcox <willy@infradead.org>,
device-mapper development <dm-devel@redhat.com>,
Linux NVDIMM <nvdimm@lists.linux.dev>,
linux-s390 <linux-s390@vger.kernel.org>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
virtualization@lists.linux-foundation.org
Subject: Re: [PATCH 4/5] dax: remove the copy_from_iter and copy_to_iter methods
Date: Mon, 13 Dec 2021 09:24:20 +0100 [thread overview]
Message-ID: <20211213082420.GC21462@lst.de> (raw)
In-Reply-To: <CAPcyv4gZjkVW0vwNLChXCCBVF8CsSZityzSVmcGAk79-mt9yOw@mail.gmail.com>
On Sun, Dec 12, 2021 at 06:39:16AM -0800, Dan Williams wrote:
> > /* flag to check if device supports synchronous flush */
> > DAXDEV_SYNC,
> > + /* do not use uncached operations to write data */
> > + DAXDEV_CACHED,
> > + /* do not use mcsafe operations to read data */
> > + DAXDEV_NOMCSAFE,
>
> Linus did not like the mcsafe name, and this brings it back. Let's
> flip the polarity to positively indicate which routine to use, and to
> match the 'nofault' style which says "copy and handle faults".
>
> /* do not leave the caches dirty after writes */
> DAXDEV_NOCACHE
>
> /* handle CPU fetch exceptions during reads */
> DAXDEV_NOMC
>
> ...and then flip the use cases around.
Sure we can do that. But let's finish the discussion if we actually
need the virtiofs special casing, as it seems pretty fishy in many
aspects.
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: Dan Williams <dan.j.williams@intel.com>
Cc: Linux NVDIMM <nvdimm@lists.linux.dev>,
linux-s390 <linux-s390@vger.kernel.org>,
Dave Jiang <dave.jiang@intel.com>,
Vasily Gorbik <gor@linux.ibm.com>,
Mike Snitzer <snitzer@redhat.com>,
Miklos Szeredi <miklos@szeredi.hu>,
Vishal Verma <vishal.l.verma@intel.com>,
Heiko Carstens <hca@linux.ibm.com>,
Matthew Wilcox <willy@infradead.org>,
virtualization@lists.linux-foundation.org,
Christian Borntraeger <borntraeger@de.ibm.com>,
device-mapper development <dm-devel@redhat.com>,
Vivek Goyal <vgoyal@redhat.com>,
Stefan Hajnoczi <stefanha@redhat.com>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
Ira Weiny <ira.weiny@intel.com>, Christoph Hellwig <hch@lst.de>,
Alasdair Kergon <agk@redhat.com>
Subject: Re: [PATCH 4/5] dax: remove the copy_from_iter and copy_to_iter methods
Date: Mon, 13 Dec 2021 09:24:20 +0100 [thread overview]
Message-ID: <20211213082420.GC21462@lst.de> (raw)
In-Reply-To: <CAPcyv4gZjkVW0vwNLChXCCBVF8CsSZityzSVmcGAk79-mt9yOw@mail.gmail.com>
On Sun, Dec 12, 2021 at 06:39:16AM -0800, Dan Williams wrote:
> > /* flag to check if device supports synchronous flush */
> > DAXDEV_SYNC,
> > + /* do not use uncached operations to write data */
> > + DAXDEV_CACHED,
> > + /* do not use mcsafe operations to read data */
> > + DAXDEV_NOMCSAFE,
>
> Linus did not like the mcsafe name, and this brings it back. Let's
> flip the polarity to positively indicate which routine to use, and to
> match the 'nofault' style which says "copy and handle faults".
>
> /* do not leave the caches dirty after writes */
> DAXDEV_NOCACHE
>
> /* handle CPU fetch exceptions during reads */
> DAXDEV_NOMC
>
> ...and then flip the use cases around.
Sure we can do that. But let's finish the discussion if we actually
need the virtiofs special casing, as it seems pretty fishy in many
aspects.
_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
next prev parent reply other threads:[~2021-12-13 8:26 UTC|newest]
Thread overview: 97+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-09 6:38 [dm-devel] devirtualize kernel access to DAX Christoph Hellwig
2021-12-09 6:38 ` Christoph Hellwig
2021-12-09 6:38 ` Christoph Hellwig
2021-12-09 6:38 ` [dm-devel] [PATCH 1/5] uio: remove copy_from_iter_flushcache() and copy_mc_to_iter() Christoph Hellwig
2021-12-09 6:38 ` Christoph Hellwig
2021-12-09 6:38 ` Christoph Hellwig
2021-12-12 14:22 ` [dm-devel] " Dan Williams
2021-12-12 14:22 ` Dan Williams
2021-12-12 14:22 ` Dan Williams
2021-12-13 8:27 ` [dm-devel] " Christoph Hellwig
2021-12-13 8:27 ` Christoph Hellwig
2021-12-13 8:27 ` Christoph Hellwig
2021-12-09 6:38 ` [dm-devel] [PATCH 2/5] dax: simplify dax_synchronous and set_dax_synchronous Christoph Hellwig
2021-12-09 6:38 ` Christoph Hellwig
2021-12-09 6:38 ` Christoph Hellwig
2021-12-09 21:03 ` [dm-devel] " Pankaj Gupta
2021-12-09 21:03 ` Pankaj Gupta
2021-12-12 14:23 ` [dm-devel] " Dan Williams
2021-12-12 14:23 ` Dan Williams
2021-12-12 14:23 ` Dan Williams
2021-12-09 6:38 ` [dm-devel] [PATCH 3/5] dax: remove the DAXDEV_F_SYNC flag Christoph Hellwig
2021-12-09 6:38 ` Christoph Hellwig
2021-12-09 6:38 ` Christoph Hellwig
2021-12-12 14:24 ` [dm-devel] " Dan Williams
2021-12-12 14:24 ` Dan Williams
2021-12-12 14:24 ` Dan Williams
2021-12-13 8:40 ` [dm-devel] " Pankaj Gupta
2021-12-13 8:40 ` Pankaj Gupta
2021-12-09 6:38 ` [dm-devel] [PATCH 4/5] dax: remove the copy_from_iter and copy_to_iter methods Christoph Hellwig
2021-12-09 6:38 ` Christoph Hellwig
2021-12-09 6:38 ` Christoph Hellwig
2021-12-10 14:16 ` [dm-devel] " Vivek Goyal
2021-12-10 14:16 ` Vivek Goyal
2021-12-10 14:16 ` Vivek Goyal
2021-12-12 14:44 ` [dm-devel] " Dan Williams
2021-12-12 14:44 ` Dan Williams
2021-12-12 14:44 ` Dan Williams
2021-12-13 8:23 ` [dm-devel] " Christoph Hellwig
2021-12-13 8:23 ` Christoph Hellwig
2021-12-13 8:23 ` Christoph Hellwig
2021-12-14 14:22 ` [dm-devel] " Vivek Goyal
2021-12-14 14:22 ` Vivek Goyal
2021-12-14 14:22 ` Vivek Goyal
2021-12-14 16:41 ` [dm-devel] " Dan Williams
2021-12-14 16:41 ` Dan Williams
2021-12-14 16:41 ` Dan Williams
2021-12-14 20:32 ` [dm-devel] " Vivek Goyal
2021-12-14 20:32 ` Vivek Goyal
2021-12-14 20:32 ` Vivek Goyal
2021-12-14 23:43 ` [dm-devel] " Dan Williams
2021-12-14 23:43 ` Dan Williams
2021-12-14 23:43 ` Dan Williams
2021-12-15 15:52 ` [dm-devel] " Vivek Goyal
2021-12-15 15:52 ` Vivek Goyal
2021-12-15 15:52 ` Vivek Goyal
2021-12-15 16:46 ` [dm-devel] " Dan Williams
2021-12-15 16:46 ` Dan Williams
2021-12-15 16:46 ` Dan Williams
2021-12-15 10:30 ` [dm-devel] " Stefan Hajnoczi
2021-12-15 10:30 ` Stefan Hajnoczi
2021-12-15 10:30 ` Stefan Hajnoczi
2021-12-15 15:43 ` [dm-devel] " Vivek Goyal
2021-12-15 15:43 ` Vivek Goyal
2021-12-15 15:43 ` Vivek Goyal
2021-12-15 17:27 ` [dm-devel] " Stefan Hajnoczi
2021-12-15 17:27 ` Stefan Hajnoczi
2021-12-15 17:27 ` Stefan Hajnoczi
2021-12-13 16:17 ` [dm-devel] " Vivek Goyal
2021-12-13 16:17 ` Vivek Goyal
2021-12-13 16:17 ` Vivek Goyal
2021-12-12 14:39 ` [dm-devel] " Dan Williams
2021-12-12 14:39 ` Dan Williams
2021-12-12 14:39 ` Dan Williams
2021-12-13 8:24 ` Christoph Hellwig [this message]
2021-12-13 8:24 ` Christoph Hellwig
2021-12-13 8:24 ` Christoph Hellwig
2021-12-09 6:38 ` [dm-devel] [PATCH 5/5] dax: always use _copy_mc_to_iter in dax_copy_to_iter Christoph Hellwig
2021-12-09 6:38 ` Christoph Hellwig
2021-12-09 6:38 ` Christoph Hellwig
2021-12-10 14:05 ` [dm-devel] " Vivek Goyal
2021-12-10 14:05 ` Vivek Goyal
2021-12-10 14:05 ` Vivek Goyal
2021-12-12 14:48 ` [dm-devel] " Dan Williams
2021-12-12 14:48 ` Dan Williams
2021-12-12 14:48 ` Dan Williams
2021-12-13 8:20 ` [dm-devel] " Christoph Hellwig
2021-12-13 8:20 ` Christoph Hellwig
2021-12-13 8:20 ` Christoph Hellwig
2021-12-13 16:43 ` [dm-devel] " Dan Williams
2021-12-13 16:43 ` Dan Williams
2021-12-13 16:43 ` Dan Williams
2021-12-14 13:59 ` [dm-devel] " Vivek Goyal
2021-12-14 13:59 ` Vivek Goyal
2021-12-14 13:59 ` Vivek Goyal
2021-12-12 15:03 ` [dm-devel] " Dan Williams
2021-12-12 15:03 ` Dan Williams
2021-12-12 15:03 ` Dan Williams
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