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authorLinus Torvalds <torvalds@linux-foundation.org>2008-07-30 10:43:56 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-07-30 10:43:56 -0700
commit660fc1f4d88b0f5e4bb936e4a5a9b95b70df9e58 (patch)
treea5b5de254f9b4378d77171e2a5d6496ec8e3e3f5 /include/linux
parent3dd730f2b49f101b90d283c3efc4e6cd826dd8f6 (diff)
parentce0ad7f0952581ba75ab6aee55bb1ed9bb22cf4f (diff)
Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: powerpc/mm: Lockless get_user_pages_fast() for 64-bit (v3) powerpc: Don't use the wrong thread_struct for ptrace get/set VSX regs powerpc: Fix ptrace buffer size for VSX powerpc: Correctly hookup PTRACE_GET/SETVSRREGS for 32 bit processes ide/powermac: Fix use of uninitialized pointer on media-bay powerpc: Allow non-hcall return values for lparcfg writes ipmi/powerpc: Use linux/of_{device,platform}.h instead of asm powerpc/fsl: proliferate simple-bus compatibility to soc nodes Documentation: remove old sbc8260 board specific information cpm2: Rework baud rate generators configuration to support external clocks. powerpc: rtc_cmos_setup: assign interrupts only if there is i8259 PIC cpm_uart: Add generic clock API support to set baudrates cpm_uart: Modem control lines support powerpc: implement GPIO LIB API on CPM1 Freescale SoC. cpm2: Implement GPIO LIB API on CPM2 Freescale SoC. powerpc: Fix 8xx build failure powerpc: clean up the Book-E HW watchpoint support
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/pagemap.h23
1 files changed, 23 insertions, 0 deletions
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index a39b38ccdc9..69ed3cb1197 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -143,6 +143,29 @@ static inline int page_cache_get_speculative(struct page *page)
return 1;
}
+/*
+ * Same as above, but add instead of inc (could just be merged)
+ */
+static inline int page_cache_add_speculative(struct page *page, int count)
+{
+ VM_BUG_ON(in_interrupt());
+
+#if !defined(CONFIG_SMP) && defined(CONFIG_CLASSIC_RCU)
+# ifdef CONFIG_PREEMPT
+ VM_BUG_ON(!in_atomic());
+# endif
+ VM_BUG_ON(page_count(page) == 0);
+ atomic_add(count, &page->_count);
+
+#else
+ if (unlikely(!atomic_add_unless(&page->_count, count, 0)))
+ return 0;
+#endif
+ VM_BUG_ON(PageCompound(page) && page != compound_head(page));
+
+ return 1;
+}
+
static inline int page_freeze_refs(struct page *page, int count)
{
return likely(atomic_cmpxchg(&page->_count, count, 0) == count);