From: Christoph Hellwig <hch@lst.de>
To: "Nicholas A. Bellinger" <nab@linux-iscsi.org>
Cc: linux-scsi <linux-scsi@vger.kernel.org>,
linux-kernel <linux-kernel@vger.kernel.org>,
James Bottomley <James.Bottomley@suse.de>,
Jeff Garzik <jeff@garzik.org>, Christoph Hellwig <hch@lst.de>,
FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>,
Hannes Reinecke <hare@suse.de>,
Mike Christie <michaelc@cs.wisc.edu>,
Mike Anderson <andmike@linux.vnet.ibm.com>,
Tejun Heo <tj@kernel.org>, Vasu Dev <vasu.dev@linux.intel.com>,
Tim Chen <tim.c.chen@linux.intel.com>,
Andi Kleen <ak@linux.intel.com>,
Ravi Anand <ravi.anand@qlogic.com>,
Andrew Vasquez <andrew.vasquez@qlogic.com>,
Joe Eykholt <jeykholt@cisco.com>,
James Smart <james.smart@emulex.com>,
Douglas Gilbert <dgilbert@interlog.com>,
adam radford <aradford@gmail.com>,
Kashyap Desai <Kashyap.Desai@lsi.com>,
MPTFusionLinux <DL-MPTFusionLinux@lsi.com>
Subject: Re: [PATCH 02/12] scsi: Add IRQ_DISABLE_SCSI_QCMD wrapper
Date: Mon, 20 Dec 2010 11:48:20 +0100 [thread overview]
Message-ID: <20101220104820.GA2752@lst.de> (raw)
In-Reply-To: <1292793727-31957-3-git-send-email-nab@linux-iscsi.org>
On Sun, Dec 19, 2010 at 01:21:57PM -0800, Nicholas A. Bellinger wrote:
> From: Nicholas Bellinger <nab@linux-iscsi.org>
>
> This patch adds a IRQ_DISABLE_SCSI_QCMD() wrapper macro used by LLDs
> that can now run in host_lock less mode, but still need interrupts disabled
> using local_irq_save() before calling their lld_queuecommand() dispatcher.
>
> jgarzik says this method is in fact slower than doing a spin_lock_irqsave() on
> internal lib_lld_queuecommand() callers (as is done in libiscsi and libata)
> but is still needed by the majority of lock_less LLDs.
As mentioned before, please don't add more macro obsfucation - The
initial one Jeff added was ok for the quick transition and avoiding to
have two methods, but any additional one is not helpful.
In addition there's really no reason to every use this one. There is
not reason to disable local irqs in a driver without taking a spinlock.
next prev parent reply other threads:[~2010-12-20 10:48 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-12-19 21:21 [PATCH 00/12] LLD host_lock-less conversion status for .38 Nicholas A. Bellinger
2010-12-19 21:21 ` [PATCH 01/12] libiscsi: Convert to host_lock less w/ interrupts disabled internally Nicholas A. Bellinger
2010-12-19 23:38 ` Matthew Wilcox
2010-12-20 1:15 ` Nicholas A. Bellinger
2010-12-20 1:22 ` Nicholas A. Bellinger
2010-12-20 2:07 ` Matthew Wilcox
2010-12-20 9:30 ` Nicholas A. Bellinger
[not found] ` <1292837413.20840.47.camel-Y1+j5t8j3WgjMeEPmliV8E/sVC8ogwMJ@public.gmane.org>
2010-12-21 0:36 ` Mike Christie
2010-12-23 21:23 ` Nicholas A. Bellinger
[not found] ` <1293139434.4649.122.camel-Y1+j5t8j3WgjMeEPmliV8E/sVC8ogwMJ@public.gmane.org>
2010-12-27 3:44 ` Mike Christie
2010-12-21 0:42 ` Mike Christie
2010-12-21 10:53 ` Boaz Harrosh
2010-12-21 23:43 ` Mike Christie
2010-12-23 21:33 ` Nicholas A. Bellinger
2010-12-19 21:21 ` [PATCH 02/12] scsi: Add IRQ_DISABLE_SCSI_QCMD wrapper Nicholas A. Bellinger
2010-12-20 10:48 ` Christoph Hellwig [this message]
2010-12-19 21:21 ` [PATCH 03/12] libsas: Convert to host_lock less w/ interrupts disabled externally Nicholas A. Bellinger
2010-12-20 8:58 ` Boaz Harrosh
2010-12-20 9:33 ` Nicholas A. Bellinger
2010-12-19 21:21 ` [PATCH 04/12] message: " Nicholas A. Bellinger
2010-12-19 21:22 ` [PATCH 05/12] fnic: " Nicholas A. Bellinger
2010-12-19 21:22 ` [PATCH 06/12] lpfc: " Nicholas A. Bellinger
2010-12-19 21:22 ` [PATCH 07/12] qla2xxx: " Nicholas A. Bellinger
2010-12-19 23:11 ` Matthew Wilcox
2010-12-20 0:19 ` Jeff Garzik
2010-12-20 1:07 ` Nicholas A. Bellinger
2010-12-20 9:23 ` Nicholas A. Bellinger
2010-12-21 0:37 ` Madhu Iyengar
2010-12-23 21:49 ` Nicholas A. Bellinger
2011-01-03 18:25 ` Madhu Iyengar
2011-01-03 18:37 ` James Bottomley
2011-01-03 20:42 ` Madhu Iyengar
2010-12-19 21:22 ` [PATCH 08/12] qla4xxx: " Nicholas A. Bellinger
2010-12-19 21:22 ` [PATCH 09/12] scsi_debug: Convert to host_lock less Nicholas A. Bellinger
2010-12-19 21:22 ` [PATCH 10/12] megaraid_sas: Add smp_mb__after_atomic_*() for instance->fw_outstanding Nicholas A. Bellinger
2010-12-19 21:22 ` [PATCH 11/12] megaraid_sas: Convert instance->issuepend_done to atomic_t Nicholas A. Bellinger
2010-12-19 21:22 ` [PATCH 12/12] megaraid_sas: Convert SHT->queuecommand() to run host_lock-less Nicholas A. Bellinger
2010-12-20 15:08 ` [PATCH 00/12] LLD host_lock-less conversion status for .38 Desai, Kashyap
2010-12-20 19:33 ` adam radford
2010-12-23 21:17 ` Nicholas A. Bellinger
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