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From: "Kani, Toshimitsu" <toshi.kani@hpe.com>
To: "joe@perches.com" <joe@perches.com>,
	"dan.j.williams@intel.com" <dan.j.williams@intel.com>,
	"akpm@linux-foundation.org" <akpm@linux-foundation.org>
Cc: "linux-nvdimm@lists.01.org" <linux-nvdimm@lists.01.org>,
	"david@fromorbit.com" <david@fromorbit.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"viro@zeniv.linux.org.uk" <viro@zeniv.linux.org.uk>,
	"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>
Subject: Re: [PATCH v5] DAX: enable iostat for read/write
Date: Thu, 12 Jan 2017 18:26:42 +0000	[thread overview]
Message-ID: <1484248944.2029.5.camel@hpe.com> (raw)
In-Reply-To: <1484244141.3065.20.camel@perches.com>

On Thu, 2017-01-12 at 10:02 -0800, Joe Perches wrote:
> On Thu, 2017-01-12 at 11:38 -0700, Toshi Kani wrote:
> > DAX IO path does not support iostat, but its metadata IO path does.
> > Therefore, iostat shows metadata IO statistics only, which has been
> > confusing to users.
> 
> []
> > diff --git a/fs/dax.c b/fs/dax.c
> 
> []
> > @@ -1058,12 +1058,24 @@ dax_iomap_rw(struct kiocb *iocb, struct
> > iov_iter *iter,
> >  {
> >  	struct address_space *mapping = iocb->ki_filp->f_mapping;
> >  	struct inode *inode = mapping->host;
> > +	struct gendisk *disk = inode->i_sb->s_bdev->bd_disk;
> >  	loff_t pos = iocb->ki_pos, ret = 0, done = 0;
> >  	unsigned flags = 0;
> > +	unsigned long start = 0;
> > +	int do_acct = blk_queue_io_stat(disk->queue);
> >  
> >  	if (iov_iter_rw(iter) == WRITE)
> >  		flags |= IOMAP_WRITE;
> >  
> > +	if (do_acct) {
> > +		sector_t sec = iov_iter_count(iter) >> 9;
> > +
> > +		start = jiffies;
> > +		generic_start_io_acct(iov_iter_rw(iter),
> > +				      min_t(unsigned long, 1,
> > sec),
> 
> I believe I mislead you with a thinko.
> 
> Your original code was
> 	(!sec) ? 1 : sec
> and I suggested incorrectly using min_t
> 
> It should of course be max_t.  Sorry.

My bad. I should have caught it.

> Also, as sec is now sector_t (u64), perhaps this
> unsigned long cast is incorrect.

I see. Since iov_iter_count() returns a size_t value, I will use
'size_t' for 'sec' as you originally suggested. 

Thanks,
-Toshi
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm

WARNING: multiple messages have this Message-ID (diff)
From: "Kani, Toshimitsu" <toshi.kani@hpe.com>
To: "joe@perches.com" <joe@perches.com>,
	"dan.j.williams@intel.com" <dan.j.williams@intel.com>,
	"akpm@linux-foundation.org" <akpm@linux-foundation.org>
Cc: "viro@zeniv.linux.org.uk" <viro@zeniv.linux.org.uk>,
	"david@fromorbit.com" <david@fromorbit.com>,
	"linux-nvdimm@lists.01.org" <linux-nvdimm@ml01.01.org>,
	"ross.zwisler@linux.intel.com" <ross.zwisler@linux.intel.com>,
	"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v5] DAX: enable iostat for read/write
Date: Thu, 12 Jan 2017 18:26:42 +0000	[thread overview]
Message-ID: <1484248944.2029.5.camel@hpe.com> (raw)
In-Reply-To: <1484244141.3065.20.camel@perches.com>

On Thu, 2017-01-12 at 10:02 -0800, Joe Perches wrote:
> On Thu, 2017-01-12 at 11:38 -0700, Toshi Kani wrote:
> > DAX IO path does not support iostat, but its metadata IO path does.
> > Therefore, iostat shows metadata IO statistics only, which has been
> > confusing to users.
> 
> []
> > diff --git a/fs/dax.c b/fs/dax.c
> 
> []
> > @@ -1058,12 +1058,24 @@ dax_iomap_rw(struct kiocb *iocb, struct
> > iov_iter *iter,
> >  {
> >  	struct address_space *mapping = iocb->ki_filp->f_mapping;
> >  	struct inode *inode = mapping->host;
> > +	struct gendisk *disk = inode->i_sb->s_bdev->bd_disk;
> >  	loff_t pos = iocb->ki_pos, ret = 0, done = 0;
> >  	unsigned flags = 0;
> > +	unsigned long start = 0;
> > +	int do_acct = blk_queue_io_stat(disk->queue);
> >  
> >  	if (iov_iter_rw(iter) == WRITE)
> >  		flags |= IOMAP_WRITE;
> >  
> > +	if (do_acct) {
> > +		sector_t sec = iov_iter_count(iter) >> 9;
> > +
> > +		start = jiffies;
> > +		generic_start_io_acct(iov_iter_rw(iter),
> > +				      min_t(unsigned long, 1,
> > sec),
> 
> I believe I mislead you with a thinko.
> 
> Your original code was
> 	(!sec) ? 1 : sec
> and I suggested incorrectly using min_t
> 
> It should of course be max_t.  Sorry.

My bad. I should have caught it.

> Also, as sec is now sector_t (u64), perhaps this
> unsigned long cast is incorrect.

I see. Since iov_iter_count() returns a size_t value, I will use
'size_t' for 'sec' as you originally suggested. 

Thanks,
-Toshi

WARNING: multiple messages have this Message-ID (diff)
From: "Kani, Toshimitsu" <toshi.kani@hpe.com>
To: "joe@perches.com" <joe@perches.com>,
	"dan.j.williams@intel.com" <dan.j.williams@intel.com>,
	"akpm@linux-foundation.org" <akpm@linux-foundation.org>
Cc: "viro@zeniv.linux.org.uk" <viro@zeniv.linux.org.uk>,
	"david@fromorbit.com" <david@fromorbit.com>,
	"linux-nvdimm@lists.01.org" <linux-nvdimm@lists.01.org>,
	"ross.zwisler@linux.intel.com" <ross.zwisler@linux.intel.com>,
	"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v5] DAX: enable iostat for read/write
Date: Thu, 12 Jan 2017 18:26:42 +0000	[thread overview]
Message-ID: <1484248944.2029.5.camel@hpe.com> (raw)
In-Reply-To: <1484244141.3065.20.camel@perches.com>

On Thu, 2017-01-12 at 10:02 -0800, Joe Perches wrote:
> On Thu, 2017-01-12 at 11:38 -0700, Toshi Kani wrote:
> > DAX IO path does not support iostat, but its metadata IO path does.
> > Therefore, iostat shows metadata IO statistics only, which has been
> > confusing to users.
> 
> []
> > diff --git a/fs/dax.c b/fs/dax.c
> 
> []
> > @@ -1058,12 +1058,24 @@ dax_iomap_rw(struct kiocb *iocb, struct
> > iov_iter *iter,
> >  {
> >  	struct address_space *mapping = iocb->ki_filp->f_mapping;
> >  	struct inode *inode = mapping->host;
> > +	struct gendisk *disk = inode->i_sb->s_bdev->bd_disk;
> >  	loff_t pos = iocb->ki_pos, ret = 0, done = 0;
> >  	unsigned flags = 0;
> > +	unsigned long start = 0;
> > +	int do_acct = blk_queue_io_stat(disk->queue);
> >  
> >  	if (iov_iter_rw(iter) == WRITE)
> >  		flags |= IOMAP_WRITE;
> >  
> > +	if (do_acct) {
> > +		sector_t sec = iov_iter_count(iter) >> 9;
> > +
> > +		start = jiffies;
> > +		generic_start_io_acct(iov_iter_rw(iter),
> > +				      min_t(unsigned long, 1,
> > sec),
> 
> I believe I mislead you with a thinko.
> 
> Your original code was
> 	(!sec) ? 1 : sec
> and I suggested incorrectly using min_t
> 
> It should of course be max_t.  Sorry.

My bad. I should have caught it.

> Also, as sec is now sector_t (u64), perhaps this
> unsigned long cast is incorrect.

I see. Since iov_iter_count() returns a size_t value, I will use
'size_t' for 'sec' as you originally suggested. 

Thanks,
-Toshi

  reply	other threads:[~2017-01-12 18:26 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-01-12 18:38 [PATCH v5] DAX: enable iostat for read/write Toshi Kani
2017-01-12 18:38 ` Toshi Kani
2017-01-12 18:38 ` Toshi Kani
2017-01-12 18:02 ` Joe Perches
2017-01-12 18:02   ` Joe Perches
2017-01-12 18:02   ` Joe Perches
2017-01-12 18:26   ` Kani, Toshimitsu [this message]
2017-01-12 18:26     ` Kani, Toshimitsu
2017-01-12 18:26     ` Kani, Toshimitsu
2017-01-25 11:19 ` Christoph Hellwig
2017-01-25 11:19   ` Christoph Hellwig
2017-01-25 11:19   ` Christoph Hellwig
2017-01-25 15:15   ` Jeff Moyer
2017-01-25 15:55     ` Kani, Toshimitsu

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