On Mon, 2010-11-29 at 23:26 -0700, Yang, Bo wrote: > Nicholas, > > Thanks for your patches (patches 1 -3). We need to build the driver and provide it to our testing team to do > the full verification on lock_less kernel. > The patch 2 and patch 3 changed the driver's major routines (I/O, get/return cmds routines and OCR routine). > I will keep update after we did the internal patch re-view for those changes as well as the testing team > give us the report. > Great, thanks for moving forward on the lock_less conversion.. Please let me know if you have any other questions. > By the way, can you send me the full link of: lio-core-2.6.git/lock_less-LLDs-for-38-v2? I am try to understand the changes for patch 3 The patch #3 in full context is available here: http://git.kernel.org/?p=linux/kernel/git/nab/lio-core-2.6.git;a=blob;f=drivers/scsi/megaraid/megaraid_sas.c;h=c42e1e4ef8c9923d9a930fa631f8d65455afadd6;hb=lock_less-LLDs-for-38-v2 Thanks! --nab > + struct megasas_cmd *cmd; > unsigned long flags; > - struct megasas_cmd *cmd = NULL; > > And > > +megasas_get_cmd(struct megasas_instance *instance) { > + struct megasas_cmd *cmd; > + unsigned long flags; > + > + spin_lock_irqsave(&instance->cmd_pool_lock, flags); > + cmd = __megasas_get_cmd(instance); > spin_unlock_irqrestore(&instance->cmd_pool_lock, flags); > + > return cmd; > } > > Regards, > > Bo Yang > > -----Original Message----- > From: linux-scsi-owner@xxxxxxxxxxxxxxx [mailto:linux-scsi-owner@xxxxxxxxxxxxxxx] On Behalf Of Nicholas A. Bellinger > Sent: Sunday, November 28, 2010 2:18 AM > To: linux-scsi; Hannes Reinecke; Yang, Bo > Cc: Christoph Hellwig; James Bottomley; Nicholas Bellinger > Subject: [PATCH 0/3] megaraid_sas: Convert to host_lock less w/ interrupts disabled internally > > From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx> > > Greetings Hannes, Bo and Co, > > This series converts megaraid_sas to run in modern host_lock-less mode > for >= .37-rc3+ with interrupts disabled internally around megasas_instance->hba_lock. > This series is currently living in lio-core-2.6.git/lock_less-LLDs-for-38-v2, > and is intended for .38 mainline code. > > The first patch adds a handful of missing barriers around instance->fw_outstanding > usage w/ atomic_add() and atomic_dec(). > > The second converts instance->issuepend_done to an atomic_t, along with > the necessary assignments in order to run w/ Scsi_Host->host_lock, and > without instance->hba_lock. > > The third patch does the actual conversion, and adds a __megasas_get_cmd() > usased by megasas_queue_command() w/ instance->hba_lock, along with > being held for megasas_build_ldio() and megasas_build_dcdb() in order > to locate the proper frame for struct megasas_cmd. This is really the > one major change in order to get host_lock-less to function with interrupts > disabled around hba_lock. > > So far this has been tested with Hannes's QEMU 8708EM2 HBA emulation with > TCM_Loop backends using SG_IO from KVM host in a paired Host/Guest .37-rc3 > environment. This has not been tested on real silicon yet, but I believe > this series should be working there as well. > > Comments are welcome, thanks! > > Signed-off-by: Nicholas A. Bellinger <nab@xxxxxxxxxxxxxxx> > > Nicholas Bellinger (3): > megaraid_sas: Add smp_mb__after_atomic_*() for > instance->fw_outstanding > megaraid_sas: Convert instance->issuepend_done to atomic_t > megaraid_sas: Convert SHT->queuecommand() to run host_lock-less > > drivers/scsi/megaraid/megaraid_sas.c | 84 ++++++++++++++++++++++----------- > drivers/scsi/megaraid/megaraid_sas.h | 2 +- > 2 files changed, 57 insertions(+), 29 deletions(-) > -- 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
