[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH 3 of 5] rombios/ata: Reading this status register has no relevant side effects
So taking two traps when one will do is pointless. This codepath is on the int 0x13 hot path, and removing it has about a 30% reduction in the number of traps to Qemu during Win7 boot. Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> diff -r c223c044afbf -r a8645d836a0e tools/firmware/rombios/rombios.c --- a/tools/firmware/rombios/rombios.c +++ b/tools/firmware/rombios/rombios.c @@ -2540,7 +2540,6 @@ static int await_ide(when_done,base,time Bit32u time=0,last=0; Bit16u status; Bit8u result; - status = inb(base + ATA_CB_STAT); // for the times you're supposed to throw one away for(;;) { status = inb(base+ATA_CB_STAT); time++; _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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