choice prompt "Preemption Model" default PREEMPT_NONE config PREEMPT_NONE bool "No Forced Preemption (Server)" help This is the traditional Linux preemption model, geared towards throughput. It will still provide good latencies most of the time, but there are no guarantees and occasional longer delays are possible. Select this option if you are building a kernel for a server or scientific/computation system, or if you want to maximize the raw processing power of the kernel, irrespective of scheduling latencies. config PREEMPT_VOLUNTARY bool "Voluntary Kernel Preemption (Desktop)" help This option reduces the latency of the kernel by adding more "explicit preemption points" to the kernel code. These new preemption points have been selected to reduce the maximum latency of rescheduling, providing faster application reactions, at the cost of slightly lower throughput. This allows reaction to interactive events by allowing a low priority process to voluntarily preempt itself even if it is in kernel mode executing a system call. This allows applications to run more 'smoothly' even when the system is under load. Select this if you are building a kernel for a desktop system. config PREEMPT bool "Preemptible Kernel (Low-Latency Desktop)" select PREEMPT_COUNT select UNINLINE_SPIN_UNLOCK if !ARCH_INLINE_SPIN_UNLOCK help This option reduces the latency of the kernel by making all kernel code (that is not executing in a critical section) preemptible. This allows reaction to interactive events by permitting a low priority process to be preempted involuntarily even if it is in kernel mode executing a system call and would otherwise not be about to reach a natural preemption point. This allows applications to run more 'smoothly' even when the system is under load, at the cost of slightly lower throughput and a slight runtime overhead to kernel code. Select this if you are building a kernel for a desktop or embedded system with latency requirements in the milliseconds range. endchoice config PREEMPT_COUNT boolght' method='get' action='/cgit.cgi/linux/net-next.git/log/include/soc/brcmstb'>
path: root/include/soc/brcmstb
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authorChristoph Hellwig <hch@lst.de>2017-01-30 13:15:41 +0100
committerBjorn Helgaas <bhelgaas@google.com>2017-02-02 10:35:46 -0600
commitdfef358bd1beb4e7b5c94eca944be9cd23dfc752 (patch)
treeb9a2afb38a4c2ac8ad31f49ec0d71fe9e5b1994c /include/soc/brcmstb
parent030305d69fc6963c16003f50d7e8d74b02d0a143 (diff)
PCI/MSI: Don't apply affinity if there aren't enough vectors left
Bart reported a problem wіth an out of bounds access in the low-level IRQ affinity code, which we root caused to the qla2xxx driver assigning all its MSI-X vectors to the pre and post vectors, and not having any left for the actually spread IRQs. Fix this issue by not asking for affinity assignment when there are no vectors to assign left. Fixes: 402723ad5c62 ("PCI/MSI: Provide pci_alloc_irq_vectors_affinity()") Link: https://lkml.kernel.org/r/1485359225.3093.3.camel@sandisk.com Reported-by: Bart Van Assche <bart.vanassche@sandisk.com> Tested-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'include/soc/brcmstb')