On 04.12.23 06:46, Michael Paquier wrote:
On Mon, Dec 04, 2023 at 06:59:13AM +0530, Bharath Rupireddy wrote:
The commit 44cac934 replaced "char buf[BLCKSZ]" with PGAlignedBlock to
avoid issues on alignment-picky hardware. While it replaced most of the
instances, there are still some more left. How about we use PGAlignedBlock
there too, something like the attached patch? A note [2] in the commit
44cac934 says that ensuring proper alignment makes kernel data transfers
fasters and the left-over "char buf[BLCKSZ]" either do read() or write()
system calls, so it might be worth to align them with PGAlignedBlock.
Thoughts?
The buffers used to write the lock file and the TLI history file are
not page buffers, and this could make code readers think that these
are pages.
The type is called "aligned block", not "aligned buffer" or "aligned
page", so I don't think it's incorrect to try to use it.
So I am honestly not sure if there's a point in changing
them because the current code is not incorrect, isn't it? It looks
like 2042b3428d39 for the TLI history file and 52948169bcdd for the
lock file began using BLCKSZ because that was just a handy thing to
do, and because we know they would never get beyond that.
Yeah, it's not clear why these need to be block-sized. We shouldn't
perpetuate this without more clarity about this.
