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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2006-06-29 08:58:05 -0400
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2006-06-29 08:58:05 -0400
commit63b122466484e44d09af12bba33b34019757a3c2 (patch)
treed35ecad386c69ddb930adcce352d0d0a8d5d95da /drivers/s390/block/dasd_genhd.c
parent9faf06547efe11ccb51678c6805037c7377b85ee (diff)
[S390] virtual cpu accounting vs. machine checks.
If a machine checks interrupts the external or the i/o interrupt handler before they have completed the cpu time calculations, the accounting goes wrong. After the cpu returned from the machine check handler to the interrupted interrupt handler, a negative cpu time delta can occur. If the accumulated cpu time in lowcore is small enough this value can get negative as well. The next jiffy interrupt will pick up that negative value, shift it by 12 and add the now huge positive value to the cpu time of the process. To solve this the machine check handler is modified not to change any of the timestamps in the lowcore if the machine check interrupted kernel context. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'drivers/s390/block/dasd_genhd.c')
0 files changed, 0 insertions, 0 deletions