Hello, We need to come up with the best possible layout of arguments for the fallocate() system call. Various architectures have different requirements for how the arguments should look like. Since the mail chain has become huge, here is the summary of various inputs received so far. Platform: s390 -------------- s390 prefers following layout: int fallocate(int fd, loff_t offset, loff_t len, int mode) For details on why and how "int, int, loff_t, loff_t" is a problem on s390, please see Heiko's mail on 16th March. Here is the link: http://www.mail-archive.com/linux-kernel@xxxxxxxxxxxxxxx/msg133595.html Platform: ppc, arm ------------------ ppc (32 bit) has a problem with "int, loff_t, loff_t, int" layout, since this will result in a pad between fd and offset, making seven arguments total - which is not supported by ppc32. It supports only 6 arguments. Thus the desired layout by ppc32 is: int fallocate(int fd, int mode, loff_t offset, loff_t len) Even ARM prefers above kind of layout. For details please see the definition of sys_arm_sync_file_range(). Option of loff_t => high u32 + low u32 -------------------------------------- Matthew and Russell have suggested another option of breaking each "loff_t" into two "u32"s. This will result in 6 arguments in total. Following think that this is a good alternative: Matthew Wilcox, Russell King, Heiko Carstens Following do not like this idea: Chris Wedgwood What are your thoughts on this ? What layout should we finalize on ? Perhaps, since sync_file_range() system call has similar arguments, we can take hint from the challenges faced on implementing it on various architectures, and decide. Please suggest. Thanks! -- Regards, Amit Arora - To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
