Date: Mon, 15 Nov 2010 11:38:58 -0500 From: John Baldwin <jhb@freebsd.org> To: freebsd-stable@freebsd.org Subject: Re: interrupt resource clean up Message-ID: <201011151138.58149.jhb@freebsd.org> In-Reply-To: <4CE157EC.6010007@sentex.net> References: <4CE157EC.6010007@sentex.net>
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On Monday, November 15, 2010 10:55:24 am Mike Tancsa wrote: > While trying to debug an issue with an em nic, I noticed that if I > unload the kld which previously had the nic using multiple msi > interrupts, and then load it with msix disabled, vmstat -i shows some > funny output > > e.g. before > > interrupt total rate > irq4: uart0 37945 0 > irq16: siis0 90443357 55 > irq18: arcmsr0 138839249 84 > irq19: bge0 twa0 4642943 2 > irq21: ehci0 11565862 7 > irq23: ehci1 3279942 2 > cpu0: timer 3279559638 2000 > irq256: em0 1609329648 981 > irq257: em1:rx 0 756066703 461 > irq258: em1:tx 0 595711018 363 > irq259: em1:link 41186 0 > irq260: ahci0 94752814 57 > cpu1: timer 3279552436 2000 > cpu3: timer 3279552195 2000 > cpu2: timer 3279550937 2000 > Total 16422925873 10015 > > > and after > > # vmstat -i > interrupt total rate > irq4: uart0 42144 0 > irq16: siis0 93796258 54 > irq18: arcmsr0 144244159 83 > irq19: bge0 twa0 4840729 2 > irq21: ehci0 12015466 6 > irq23: ehci1 3436876 2 > cpu0: timer 3436486096 2000 > irq256: em0 1719107713 1000 > irq257: em1 767271792 446 > irq258: 605077993 352 > irq259: 41186 0 > irq260: ahci0 98454608 57 > cpu1: timer 3436478875 2000 > cpu3: timer 3436478653 2000 > cpu2: timer 3436477132 2000 > Total 17194249680 10007 > > Is this just a display issue, or are the resources still allocated ? The interrupt doesn't go away when you unload the driver and it's historical count doesn't go away. vmstat -i just hides interrupts with a count of zero, but unloading the driver doesn't zero the count, so it will stay there forever. It might get reused by a different driver that uses MSI or MSI-X if you were to kldload said driver. -- John Baldwin
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