Messages in this thread | | | From | Mikael Pettersson <> | Date | Thu, 4 Nov 2004 00:28:03 +0100 | Subject | send_sig_info() from switch_to()? |
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Is it possible to do the equivalent of send_sig_info() to current from within switch_to()? My attempts to do so have all lead to hard kernel hangs, so I guess not, but I though I'd ask anyway.
There is a HW-issue with delayed interrupts from performance counter overflows on x86 and x86-64, which, if not handled, can result in a interrupt being delivered to the wrong task. (It's only been observed with certain high-rate events.) I can work around this in the perfctr kernel extension by masking the interrupt early in switch_to()'s suspend path and manually detecting if any counters have overflowed. Normal HW-detected overflows are routed to user-space via a send_sig_info() in the interrupt handler. The problem is that calling send_sig_info() from within switch_to() to signal SW-detected overflows seems to cause kernel hangs. (I've tried it both in the suspend path and in the resume path.)
Any ideas?
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