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From: Matthew Wilcox <willy@infradead.org>
To: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-mm@kvack.org, David Hildenbrand <david@redhat.com>,
	Kent Overstreet <kent.overstreet@gmail.com>,
	Johannes Weiner <hannes@cmpxchg.org>,
	linux-fsdevel@vger.kernel.org
Subject: Re: [RFC] pgflags_t
Date: Wed, 6 Oct 2021 16:38:49 +0100	[thread overview]
Message-ID: <YV3DCX92lvOA4fni@casper.infradead.org> (raw)
In-Reply-To: <YV2/NZjsmSK6/vlB@zeniv-ca.linux.org.uk>

On Wed, Oct 06, 2021 at 03:22:29PM +0000, Al Viro wrote:
> On Wed, Oct 06, 2021 at 03:58:14PM +0100, Matthew Wilcox wrote:
> > David expressed some unease about the lack of typesafety in patches
> > 1 & 2 of the page->slab conversion [1], and I'll admit to not being
> > particularly a fan of passing around an unsigned long.  That crystallised
> > in a discussion with Kent [2] about how to lock a page when you don't know
> > its type (solution: every memory descriptor type starts with a
> > pgflags_t)
> 
> Why bother making it a struct?  What's wrong with __bitwise and letting
> sparse catch conversions?

People don't run sparse.  I happen to have a built allmodconfig tree
here and running make C=2 fs/ gives 1147 lines of warnings.  Why would
adding more warnings help?


  parent reply	other threads:[~2021-10-06 15:40 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-06 14:58 [RFC] pgflags_t Matthew Wilcox
2021-10-06 15:16 ` David Hildenbrand
2021-10-06 15:29   ` Matthew Wilcox
2021-10-06 15:22 ` Al Viro
2021-10-06 15:23   ` David Hildenbrand
2021-10-06 15:28     ` Al Viro
2021-10-06 15:32       ` David Hildenbrand
2021-10-06 15:46         ` Al Viro
2021-10-06 15:47           ` David Hildenbrand
2021-10-06 15:38   ` Matthew Wilcox [this message]
2021-10-06 15:48     ` Al Viro
2021-10-07 14:37 ` Vlastimil Babka
2021-10-07 14:48   ` Matthew Wilcox

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