From: Alex Shi <alex.shi@intel.com>
To: "Nandigama, Nagalakshmi" <Nagalakshmi.Nandigama@lsi.com>
Cc: Matthew Wilcox <matthew@wil.cx>,
"Moore, Eric" <Eric.Moore@lsi.com>,
"stable@vger.kernel.org" <stable@vger.kernel.org>,
"linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>,
"Prakash, Sathya" <Sathya.Prakash@lsi.com>,
"jejb@kernel.org" <jejb@kernel.org>
Subject: Re: [PATCH] [SCSI] mpt2sas : Fix unsafe using smp_processor_id() inpreemptible
Date: Mon, 23 Apr 2012 09:29:42 +0800 [thread overview]
Message-ID: <4F94B086.4000502@intel.com> (raw)
In-Reply-To: <A6888A6805518E4EA4AF7072A28264A6067E89B20C@inbmail02.lsi.com>
On 04/20/2012 07:00 PM, Nandigama, Nagalakshmi wrote:
> diff --git a/drivers/scsi/mpt2sas/mpt2sas_base.c b/drivers/scsi/mpt2sas/mpt2sas_base.c
> index 272fab7..0f47f56 100644
> --- a/drivers/scsi/mpt2sas/mpt2sas_base.c
> +++ b/drivers/scsi/mpt2sas/mpt2sas_base.c
> @@ -1792,7 +1792,10 @@ static inline void _base_writeq(__u64 b, volatile void __iomem *addr,
> static inline u8
> _base_get_msix_index(struct MPT2SAS_ADAPTER *ioc)
> {
> - return ioc->cpu_msix_table[smp_processor_id()];
> + int cpu = get_cpu();
> + put_cpu();
> + return ioc->cpu_msix_table[cpu];
> +
> }
If we don't care the correctness interrupt CPU. Do
preempt_enable/preempt_disable is just waste of time.
A patch like following is enough, :)
_base_get_msix_index(struct MPT2SAS_ADAPTER *ioc)
{
- return ioc->cpu_msix_table[smp_processor_id()];
+ return ioc->cpu_msix_table[raw_smp_processor_id()];
}
BTW, I didn't subscribe linux-scsi mailing list, so cc to me is
appreciated.
next prev parent reply other threads:[~2012-04-23 1:30 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-17 5:55 [PATCH] [SCSI] mpt2sas : Fix unsafe using smp_processor_id() in preemptible nagalakshmi.nandigama
2012-04-18 3:14 ` Matthew Wilcox
2012-04-18 3:35 ` Moore, Eric
2012-04-18 4:13 ` Matthew Wilcox
2012-04-20 11:00 ` [PATCH] [SCSI] mpt2sas : Fix unsafe using smp_processor_id() inpreemptible Nandigama, Nagalakshmi
2012-04-23 1:29 ` Alex Shi [this message]
2012-04-20 11:07 ` [PATCH] [SCSI] mpt2sas : Fix unsafe using smp_processor_id() in preemptible James Bottomley
2012-04-27 10:39 ` Nandigama, Nagalakshmi
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