> -----Original Message----- > From: linux-kernel-owner@xxxxxxxxxxxxxxx [mailto:linux-kernel- > owner@xxxxxxxxxxxxxxx] On Behalf Of Brian King > Sent: Thursday, September 03, 2009 5:53 PM > To: akataria@xxxxxxxxxx > Cc: James Bottomley; Rolf Eike Beer; Matthew Wilcox; Roland Dreier; Bart > Van Assche; Robert Love; Randy Dunlap; Mike Christie; linux- > scsi@xxxxxxxxxxxxxxx; LKML; Andrew Morton; pv-drivers@xxxxxxxxxx > Subject: Re: [PATCH] SCSI driver for VMware's virtual HBA - V3. > > Alok Kataria wrote: > > + > > +struct pvscsi_adapter { > > + char *mmioBase; > > + unsigned int irq; > > + u8 rev; > > + bool use_msi; > > + bool use_msix; > > + bool use_msg; > > + > > + spinlock_t hw_lock; > > Why not just use host_lock in the scsi_host structure? > Why not an adapter_resource_lock? Why block everyone @ the scsi-mid layer. Alok, (This is just a optimization.You don't need it in order to get your code merged upstream.You can always patch it later on)In fact hw_lock should be split into two locks - req_path_lock(aka tx_lock) and cmpl_path_lock(aka rx_lock). You can then have a full-duplex channel. Revised-code - ::pvscsi_acquire_context->spin_lock_irqsave(tx_lock) ::pvscsi_isr->spin_lock_irqsave(rx_lock) ::some_future_napi_style_pvrx_poll_func->spin_lock_irqsave(rx_lock) ::for aborts synchronize on the rx_lock so that you know what's completed and what's not. This is the kind of common code that should be provided by the bottom edge of the scsi-layer so that all the scsi-LLDD's can split their tx/rx paths! > Brian King > Linux on Power Virtualization > IBM Linux Technology Center > Chetan -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
