Linus Torvalds 0612cae7ec mm: add 'try_get_page()' helper function ... commit 88b1a17dfc upstream. This is the same as the traditional 'get_page()' function, but instead of unconditionally incrementing the reference count of the page, it only does so if the count was "safe". It returns whether the reference count was incremented (and is marked __must_check, since the caller obviously has to be aware of it). Also like 'get_page()', you can't use this function unless you already had a reference to the page. The intent is that you can use this exactly like get_page(), but in situations where you want to limit the maximum reference count. The code currently does an unconditional WARN_ON_ONCE() if we ever hit the reference count issues (either zero or negative), as a notification that the conditional non-increment actually happened. NOTE! The count access for the "safety" check is inherently racy, but that doesn't matter since the buffer we use is basically half the range of the reference count (ie we look at the sign of the count). Acked-by: Matthew Wilcox <willy@infradead.org> Cc: Jann Horn <jannh@google.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2019-05-04 09:20:11 +02:00
..
acpi
asm-generic	x86/unwind/orc: Fix ORC unwind table alignment	2019-03-23 20:10:10 +01:00
clocksource
crypto	crypto: speck - remove Speck	2018-11-13 11:08:46 -08:00
drm	drm: disable uncached DMA optimization for ARM and arm64	2019-03-13 14:02:40 -07:00
dt-bindings
keys	keys: Fix dependency loop between construction record and auth key	2019-03-23 20:09:48 +01:00
kvm	KVM: arm/arm64: vgic: Make vgic_dist->lpi_list_lock a raw_spinlock	2019-03-23 20:09:42 +01:00
linux	mm: add 'try_get_page()' helper function	2019-05-04 09:20:11 +02:00
math-emu
media	media: cec: keep track of outstanding transmits	2019-01-09 17:38:46 +01:00
memory
misc
net	net: netrom: Fix error cleanup path of nr_proto_init	2019-05-02 09:58:57 +02:00
pcmcia
ras
rdma	IB/rxe: Revise the ib_wr_opcode enum	2018-11-13 11:08:43 -08:00
scsi	scsi: fcoe: make use of fip_mode enum complete	2019-04-05 22:33:04 +02:00
soc
sound	ALSA: compress: Fix stop handling on compressed capture streams	2019-02-12 19:47:23 +01:00
target	scsi: target/core: Make sure that target_wait_for_sess_cmds() waits long enough	2019-01-26 09:32:38 +01:00
trace	rxrpc: Fix client call connect/disconnect race	2019-04-20 09:16:05 +02:00
uapi	netfilter: xt_cgroup: shrink size of v2 path	2019-04-20 09:16:00 +02:00
video	udlfb: handle unplug properly	2019-02-27 10:09:03 +01:00
xen	Revert "xen/balloon: Mark unallocated host memory as UNUSABLE"	2018-12-17 09:24:39 +01:00