> -----Original Message----- > From: Tabi Timur-B04825 > Sent: Wednesday, July 11, 2012 11:01 PM > To: Liu Qiang-B32616 > Cc: [email protected]; [email protected]; Vinod > Koul; [email protected]; Dan Williams; Li Yang-R58472; > [email protected] > Subject: Re: [linuxppc-release] [PATCH v2 4/4] fsl-dma: use spin_lock_bh > to instead of spin_lock_irqsave > > Qiang Liu wrote: > > Use spin_lock_bh to instead of spin_lock_irqsave for improving > performance. > > Please provide some evidence that performance has improved, as well as an > explanation why it's okay to use spin_lock_bh, and why it's faster. I compared my test result before and after this patch, write performance can improved by 15%. I will send the latest patches sooner because of Ira's concern. I will give a complete description about the improvement of spin_lock_bh().
About your question, spin_lock_bh is used in the case of bottom/half as its name, there is no need to protect a running/pending list with spin_lock_irqsave. Thanks. > -- > Timur Tabi > Linux kernel developer at Freescale _______________________________________________ Linuxppc-dev mailing list [email protected] https://lists.ozlabs.org/listinfo/linuxppc-dev
