Messages in this thread | | | Date | Fri, 10 Mar 2023 18:21:07 -0500 | From | "Theodore Ts'o" <> | Subject | Re: [PATCH] ext4: convert to DIV_ROUND_UP() in mpage_process_page_bufs() |
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On Fri, Mar 10, 2023 at 02:07:34PM +0800, Yangtao Li wrote: > Just for better readability, no code logic change.
All aside from the arguments over performance, I'm not at *all* convinced by the "it's more readable" argument.
So yeah, let's not. We have i_blkbits for a reason, and it's because shifting right is just simpler and easier.
BTW, doing a 64-bit division on a 32-bit platforms causes compile failures, which was the cause of the test bot complaint:
ld: fs/ext4/inode.o: in function `mpage_process_page_bufs': >> inode.c:(.text+0xbda): undefined reference to `__divdi3'
On 32-bit platforms --- i386 in particular --- the 64-bit division results in an out-of-line call to a helper function that is not supplied in the kernel compilation environment, so not only is it slower, it Just Doesn't Work.
- Ted
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