On Fri, 16 Nov 2018 07:58:41 -0800, Bart Van Assche wrote: > On Fri, 2018-11-16 at 14:10 +0100, David Disseldorp wrote: > > On Thu, 08 Nov 2018 15:17:45 -0800, Bart Van Assche wrote: > > > What makes you think that I dropped any of the __GFP flags? The only purpose > > > of the __GFP_NOWARN and __GFP_RETRY_MAYFAIL flags is to make kcalloc() fail > > > quickly and silently. > > > > Are you confusing __GFP_RETRY_MAYFAIL with __GFP_NORETRY here? > > No. Passing __GFP_RETRY_MAYFAIL to a memory allocation function makes the memory > allocator try less hard than without that flag. In the context of this patch we're going from __GFP_RETRY_MAYFAIL to __GFP_NORETRY (due to the kvmalloc_node() >PAGE_SIZE logic), so "fail quickly" makes more sense to me when referring to the latter. > > > I'm not dropping these flags: as one can see in the > > > kvmalloc_node() implementation that function passes these flags to > > > kmalloc_node(). The source code I'm referring to is available in mm/util.c. > > > > I see that (given tag_num * tag_size > PAGE_SIZE) __GFP_NOWARN is added > > by kvmalloc_node(), but __GFP_RETRY_MAYFAIL is dropped with your change, > > which sees __GFP_NORETRY added in the >PAGE_SIZE path. > > That's right. If you want I can mention this in the patch description. I don't think that's needed, I was just interested in the motivation for the change in __GFP flags. Cheers, David
