From: Hannes Reinecke <hare@suse.de>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: qemu-devel@nongnu.org,
Stefan Haynoczi <stefanha@linux.vnet.ibm.com>,
kvm@vger.kernel.org, Alexander Graf <agraf@suse.de>
Subject: Re: [PATCH 2/3] scsi: replace 'tag' with 'hba_private' pointer
Date: Fri, 01 Jul 2011 15:11:01 +0200 [thread overview]
Message-ID: <4E0DC765.5090200@suse.de> (raw)
In-Reply-To: <4E0D84DF.7030303@redhat.com>
On 07/01/2011 10:27 AM, Paolo Bonzini wrote:
> On 07/01/2011 09:42 AM, Hannes Reinecke wrote:
>> 'tag' is just an abstraction to identify the command
>> from the driver. So we should make that explicit by
>> replacing 'tag' with a driver-defined pointer 'hba_private'.
>> This saves the lookup for driver handling several commands
>> in parallel.
>
> This makes tracing a bit harder to follow. Perhaps you can keep the
> transport tag (a uint64_t) in the SCSIRequest for debugging purposes?
>
Hmm. The transport tag wouldn't have any meaning outside scsi-bus.c.
And it's a 64-bit value. So why can't we use the hba_private pointer
directly here?
After some I/O has been ongoing the linear 'tag' number becomes
unreadable very quickly, so there's not much difference here ...
Cheers,
Hannes
--
Dr. Hannes Reinecke zSeries & Storage
hare@suse.de +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg)
WARNING: multiple messages have this Message-ID (diff)
From: Hannes Reinecke <hare@suse.de>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Alexander Graf <agraf@suse.de>,
qemu-devel@nongnu.org, kvm@vger.kernel.org,
Stefan Haynoczi <stefanha@linux.vnet.ibm.com>
Subject: Re: [Qemu-devel] [PATCH 2/3] scsi: replace 'tag' with 'hba_private' pointer
Date: Fri, 01 Jul 2011 15:11:01 +0200 [thread overview]
Message-ID: <4E0DC765.5090200@suse.de> (raw)
In-Reply-To: <4E0D84DF.7030303@redhat.com>
On 07/01/2011 10:27 AM, Paolo Bonzini wrote:
> On 07/01/2011 09:42 AM, Hannes Reinecke wrote:
>> 'tag' is just an abstraction to identify the command
>> from the driver. So we should make that explicit by
>> replacing 'tag' with a driver-defined pointer 'hba_private'.
>> This saves the lookup for driver handling several commands
>> in parallel.
>
> This makes tracing a bit harder to follow. Perhaps you can keep the
> transport tag (a uint64_t) in the SCSIRequest for debugging purposes?
>
Hmm. The transport tag wouldn't have any meaning outside scsi-bus.c.
And it's a 64-bit value. So why can't we use the hba_private pointer
directly here?
After some I/O has been ongoing the linear 'tag' number becomes
unreadable very quickly, so there's not much difference here ...
Cheers,
Hannes
--
Dr. Hannes Reinecke zSeries & Storage
hare@suse.de +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg)
next prev parent reply other threads:[~2011-07-01 13:11 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-01 7:42 [PATCH 0/3] [v4] Megasas HBA emulation Hannes Reinecke
2011-07-01 7:42 ` [Qemu-devel] " Hannes Reinecke
2011-07-01 7:42 ` [PATCH 1/3] iov: Add 'offset' parameter to iov_to_buf() Hannes Reinecke
2011-07-01 7:42 ` [Qemu-devel] " Hannes Reinecke
2011-07-01 7:42 ` [PATCH 2/3] scsi: replace 'tag' with 'hba_private' pointer Hannes Reinecke
2011-07-01 7:42 ` [Qemu-devel] " Hannes Reinecke
2011-07-01 7:42 ` [PATCH 3/3] megasas: LSI Megaraid SAS emulation Hannes Reinecke
2011-07-01 7:42 ` [Qemu-devel] " Hannes Reinecke
2011-07-01 9:16 ` Alexander Graf
2011-07-01 9:16 ` [Qemu-devel] " Alexander Graf
2011-07-03 8:09 ` Michael S. Tsirkin
2011-07-03 8:09 ` [Qemu-devel] " Michael S. Tsirkin
2011-07-01 8:27 ` [PATCH 2/3] scsi: replace 'tag' with 'hba_private' pointer Paolo Bonzini
2011-07-01 8:27 ` [Qemu-devel] " Paolo Bonzini
2011-07-01 8:57 ` Hannes Reinecke
2011-07-01 8:57 ` [Qemu-devel] " Hannes Reinecke
2011-07-01 13:11 ` Hannes Reinecke [this message]
2011-07-01 13:11 ` Hannes Reinecke
2011-07-01 14:33 ` Paolo Bonzini
2011-07-01 14:33 ` [Qemu-devel] " Paolo Bonzini
2011-07-01 8:02 ` [PATCH 1/3] iov: Add 'offset' parameter to iov_to_buf() Alexander Graf
2011-07-01 8:02 ` [Qemu-devel] " Alexander Graf
2011-07-01 8:07 ` Hannes Reinecke
2011-07-01 8:07 ` [Qemu-devel] " Hannes Reinecke
2011-07-01 8:11 ` Alexander Graf
2011-07-01 8:11 ` [Qemu-devel] " Alexander Graf
2011-07-01 8:03 ` Paolo Bonzini
2011-07-01 8:03 ` [Qemu-devel] " Paolo Bonzini
2011-07-01 8:04 ` Hannes Reinecke
2011-07-01 8:04 ` [Qemu-devel] " Hannes Reinecke
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