Re: [Linux-nvdimm] [PATCH] pmem: Add prints at module load and unload

From: Boaz Harrosh <boaz@plexistor.com>
To: Dan Williams <dan.j.williams@intel.com>
Cc: Christoph Hellwig <hch@lst.de>,
	linux-nvdimm <linux-nvdimm@ml01.01.org>,
	linux-fsdevel <linux-fsdevel@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	X86 ML <x86@kernel.org>, Jens Axboe <axboe@kernel.dk>,
	Ingo Molnar <mingo@redhat.com>
Subject: Re: [Linux-nvdimm] [PATCH] pmem: Add prints at module load and unload
Date: Thu, 02 Apr 2015 18:47:20 +0300	[thread overview]
Message-ID: <551D6488.9090501@plexistor.com> (raw)
In-Reply-To: <CAPcyv4gRONdKn7bi2gS7RWWrNT=YuAPk-wNtJy_n_BTQq--LVw@mail.gmail.com>

On 04/02/2015 06:39 PM, Dan Williams wrote:
> On Thu, Apr 2, 2015 at 8:31 AM, Boaz Harrosh <boaz@plexistor.com> wrote:
>> Hi Christoph, Ingo
>>
>> Please consider this small patch below just a small print at module
>> load/unload so to know at user systems how things progressed.
>> As it is now, we know nothing. For any other disk kind we have two
>> tuns of prints.
>>
>> ---
>> From: Boaz Harrosh <boaz@plexistor.com>
>> Date: Thu, 2 Apr 2015 16:43:48 +0300
>> Subject: [PATCH] pmem: Add prints at module load and unload
>>
>> When debugging people's systems it is helpful
>> to see what went on. The load and unload of pmem is
>> an important event.
>>
>> The importance is the number of loaded devices and
>> error status. The exact device's addresses created
>> we can see from the other prints at e820 so no need
>> to duplicate this information.
>>
>> While at it fix up a small issue with rw flags.
> 
> Separate patch for fixes please.

Sigh, OK I was preparing this and hopping it would just
be SQUASHED into the original patch but Ingo bit me to it
and already submitted the patches.

> 
>>
>> Signed-off-by: Boaz Harrosh <boaz@plexistor.com>
>> ---
>>  drivers/block/pmem.c | 7 ++++++-
>>  1 file changed, 6 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/block/pmem.c b/drivers/block/pmem.c
>> index 988f384..3f15fbc 100644
>> --- a/drivers/block/pmem.c
>> +++ b/drivers/block/pmem.c
>> @@ -91,8 +91,9 @@ static int pmem_rw_page(struct block_device *bdev, sector_t sector,
>>  {
>>         struct pmem_device *pmem = bdev->bd_disk->private_data;
>>
>> +       rw &= WRITE;
>>         pmem_do_bvec(pmem, page, PAGE_CACHE_SIZE, 0, rw, sector);
>> -       page_endio(page, rw & WRITE, 0);
>> +       page_endio(page, rw, 0);
>>
>>         return 0;
>>  }
>> @@ -248,6 +249,9 @@ static int __init pmem_init(void)
>>         error = platform_driver_register(&pmem_driver);
>>         if (error)
>>                 unregister_blkdev(pmem_major, "pmem");
>> +
>> +       pr_info("pmem: init %d devices => %d\n",
>> +               atomic_read(&pmem_index), error);
> 
> If anything I think these should be dev_dbg().

We do not have a dev at any of this point, and it does not
belong to any specific device. Also I would like this
_info and not _dbg so to always have it, also for production.
See the chatter for a single SCSI disk the minimum we need
is just the small print that tells all that we need (for now)

Please consider as is?

Thanks
Boaz