> -----Original Message----- > From: Finn Thain [mailto:fthain@xxxxxxxxxxxxxxxxxxx] > Sent: Monday, February 8, 2021 8:57 PM > To: tanxiaofei <tanxiaofei@xxxxxxxxxx> > Cc: jejb@xxxxxxxxxxxxx; martin.petersen@xxxxxxxxxx; > linux-scsi@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > linuxarm@xxxxxxxxxxxxx > 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/?id=e58aa3d2d0cc 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@xxxxxx > m/ > _______________________________________________ > Linuxarm mailing list -- linuxarm@xxxxxxxxxxxxx > To unsubscribe Thanks Barry
