On 11/19/2012 10:02 AM, Alexander Gordeev wrote:
Take advantage of multiple MSIs implementation on x86 - on systems with IRQ remapping AHCI ports not only get assigned separate MSI vectors - but also separate IRQs. As result, interrupts generated by different ports could be serviced on different CPUs rather than on a single one. In cases when number of allocated MSIs is less than requested the Sharing Last MSI mode does not get used, no matter implemented in hardware or not. Instead, the driver assumes the advantage of multiple MSIs is negated and falls back to the single MSI mode as if MRSM bit was set (some Intel chips implement this strategy anyway - MRSM bit gets set even if the number of allocated MSIs exceeds the number of implemented ports). Signed-off-by: Alexander Gordeev <agordeev@xxxxxxxxxx> --- drivers/ata/ahci.c | 93 +++++++++++++++++++++++++++++++++++++-- drivers/ata/ahci.h | 6 +++ drivers/ata/libahci.c | 118 ++++++++++++++++++++++++++++++++++++++++++++++--- 3 files changed, 207 insertions(+), 10 deletions(-)
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