-----Original Message----- From: Finn Thain [mailto:fthain@telegraphics.com.au] Sent: Monday, February 8, 2021 8:57 PM To: tanxiaofei tanxiaofei@huawei.com Cc: jejb@linux.ibm.com; martin.petersen@oracle.com; linux-scsi@vger.kernel.org; linux-kernel@vger.kernel.org; linuxarm@openeuler.org Subject: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage optimization for SCSI drivers
On Sun, 7 Feb 2021, Xiaofei Tan wrote:
Replace spin_lock_irqsave with spin_lock in hard IRQ of SCSI drivers. There are no function changes, but may speed up if interrupt happen too often.
This change doesn't necessarily work on platforms that support nested interrupts.
Were you able to measure any benefit from this change on some other platform?
I think the code disabling irq in hardIRQ is simply wrong. Since this commit https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... genirq: Run irq handlers with interrupts disabled
interrupt handlers are definitely running in a irq-disabled context unless irq handlers enable them explicitly in the handler to permit other interrupts.
Please see also, https://lore.kernel.org/linux-scsi/89c5cb05cb844939ae684db0077f675f@h3c.co m/ _______________________________________________ Linuxarm mailing list -- linuxarm@openeuler.org To unsubscribe
Thanks Barry