Re: shmat returning NULL with 0 sized segment
Dave Gilbert <[EMAIL PROTECTED]> writes: > I'm trying to debug a weird problem with Xine - its screwing up its use > of shared memory for regions I haven't sussed yet. One odd consequence is > that it has apparently successfully managed to allocate a 0 byte chunk of > shared memory; shmat is then called with shmaddr=0 and shmflg=0; the > result of shmat is 0 > > Is this what shmat is supposed to do in this (admittedly odd) > circumstance? The error behaviour is defined in the man page as returning > -1 on error. Yes, this should be competely legal and wanted. Some programs use shmget (..,0,..) to test if the segment is there. Apparently Xine does this while setting the IPC_CREATE flag. This is legal on 2.4 (wasn't in 2.2) and gives you a 0 byte segment. shmat will give you then the legal address 0 like mmap would. Greetings Christoph - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
Re: shmat returning NULL with 0 sized segment
Dave Gilbert [EMAIL PROTECTED] writes: I'm trying to debug a weird problem with Xine - its screwing up its use of shared memory for regions I haven't sussed yet. One odd consequence is that it has apparently successfully managed to allocate a 0 byte chunk of shared memory; shmat is then called with shmaddr=0 and shmflg=0; the result of shmat is 0 Is this what shmat is supposed to do in this (admittedly odd) circumstance? The error behaviour is defined in the man page as returning -1 on error. Yes, this should be competely legal and wanted. Some programs use shmget (..,0,..) to test if the segment is there. Apparently Xine does this while setting the IPC_CREATE flag. This is legal on 2.4 (wasn't in 2.2) and gives you a 0 byte segment. shmat will give you then the legal address 0 like mmap would. Greetings Christoph - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
shmat returning NULL with 0 sized segment
Hi, I'm trying to debug a weird problem with Xine - its screwing up its use of shared memory for regions I haven't sussed yet. One odd consequence is that it has apparently successfully managed to allocate a 0 byte chunk of shared memory; shmat is then called with shmaddr=0 and shmflg=0; the result of shmat is 0 Is this what shmat is supposed to do in this (admittedly odd) circumstance? The error behaviour is defined in the man page as returning -1 on error. (Linux/Alpha 2.4.0-test8) Back to trying to find out why it decided to allocate a 0 byte chunk Dave -- Have a happy GNU millennium! -- / Dr. David Alan Gilbert | Running GNU/Linux on | Happy \ \ gro.gilbert @ treblig.org | Alpha, x86, ARM and SPARC | In Hex / \ ___|___ http://www.treblig.org |/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
shmat returning NULL with 0 sized segment
Hi, I'm trying to debug a weird problem with Xine - its screwing up its use of shared memory for regions I haven't sussed yet. One odd consequence is that it has apparently successfully managed to allocate a 0 byte chunk of shared memory; shmat is then called with shmaddr=0 and shmflg=0; the result of shmat is 0 Is this what shmat is supposed to do in this (admittedly odd) circumstance? The error behaviour is defined in the man page as returning -1 on error. (Linux/Alpha 2.4.0-test8) Back to trying to find out why it decided to allocate a 0 byte chunk Dave -- Have a happy GNU millennium! -- / Dr. David Alan Gilbert | Running GNU/Linux on | Happy \ \ gro.gilbert @ treblig.org | Alpha, x86, ARM and SPARC | In Hex / \ ___|___ http://www.treblig.org |/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
