> -----Original Message----- > From: Andy Shevchenko [mailto:andy.shevchenko@xxxxxxxxx] > Sent: Monday, May 14, 2018 3:55 PM > To: Corentin Chary; acpi4asus-user; Limonciello, Mario > Cc: Darren Hart; Platform Driver; Luis R. Rodriguez > Subject: GFP_DMA flag usage > > According to [1] the GFP_DMA (and might be __GFP_DMA32, though it's > not explicitly listed, however dell-smbios.c is listed there) has some > memory allocator performance impact and in 99.99% shows a buggy / old > hw / code. > > So, in PDx86 we have two files > > $ git grep -n GFP_DMA -- drivers/platform/x86/ > drivers/platform/x86/asus-wmi.c:343: input.pointer = > kzalloc(args.length, GFP_DMA | GFP_KERNEL); > drivers/platform/x86/dell-smbios-smm.c:138: buffer = (void > *)__get_free_page(GFP_KERNEL | GFP_DMA32); With dell-smbios if it's not in this range outlined by GFP_DMA32 the request will fail. > * drivers/net/wimax/i2400m/ - ugh, who cares about this crap anyway nowadays, my > point being another run time oddity > * drivers/net/wireless/broadcom/b43legacy/ - ugh, same > * drivers/platform/x86/asus-wmi.c - ugh same > * drivers/platform/x86/dell-smbios.c - ugh same I care about this, and I think all of the people that use the dell-* drivers that rely on this for a basis will certainly care too. > > Looking to the ASuS related code I would conclude that the guy who > submitted a patch didn't investigate it properly and root cause left > unknown. So, would be nice to have someone with actual bug reproducer > to find a better solution. > > Dell case, since we have an active maintainer, can be clarified by > contributors and Dell representative here. > > Any (additional) thoughts with regard to the topic? > > [1]: https://lwn.net/Articles/753274/ > > -- > With Best Regards, > Andy Shevchenko
