Messages in this thread | | | Date | Tue, 2 Dec 2008 20:03:03 -0800 | From | Sukadev Bhattiprolu <> | Subject | Question on SI_ASYNCIO |
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Hi,
SI_ASYNCIO is defined in include/asm-generic/siginfo.h as:
#define SI_ASYNCIO -4 /* sent by AIO completion */
The negative value makes it a 'user-space' signal according to
#define SI_FROMUSER(siptr) ((siptr)->si_code <= 0) #define SI_FROMKERNEL(siptr) ((siptr)->si_code > 0)
But this signal is generated in the kernel async_completed() - drivers/usb/core/devio.c
Am trying to understand why this is considered as a user-space signal ?
Isn't SI_ASYNCIO similar to SI_POLL or SI_MESGQ - both of which are 'kernel-signals' ?
POSIX.1 explicitly ignores async io.
Thanks,
Sukadev
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