A little long for a "knife." Sword? A Moro Barong?
A bolo - AKA a native machete. They are usually shorter than that, but I have seen some that long. They are ubiquitous all over the country, and are used where one would use a wide variety of other tools in the US. You use them to chop wood, cut brush and grass, do carpentry, you name it.
He went “amok”, which is a manic state that Filipinos occasionally get into, and is not unique to Muslims. A knife/bolo rampage in a marketplace is the traditional expression of “amok”. It is a case of impersonal rage, and there usually isn’t an individual target.
A relative of mine was killed by an “amok” in a Southern Luzon province.
There was, a couple of decades ago, an amazing series of pictures in the Manila “Bulletin” (I think) where a photographer caught the progress of an amoks rampage, where he attacked two policemen in a marketplace. One policeman was shooting at the amok, who seemed to shrug off the bullets while he went for the other, who was struggling to get his revolver out. The amok got him before he could free his gun.