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.
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
+ 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(-)
--
1.7.2.3
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