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| author | Jens Axboe <axboe@kernel.dk> | 2018-02-05 12:55:38 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2018-02-05 12:55:38 -0700 |
| commit | 9e05c864993c5442227f83ae1694a737d7a102ed (patch) | |
| tree | e35b60bb3c0c179f147e9acaad5444f1e5d9117e /include/linux/buffer_head.h | |
| parent | 3c15f3f545afa320c5e3822825a9a53c664776b6 (diff) | |
| parent | 35277995e17919ab838beae765f440674e8576eb (diff) | |
Merge branch 'master' into test
* master: (688 commits)
dt-bindings: mailbox: qcom: Document the APCS clock binding
mailbox: qcom: Create APCS child device for clock controller
mailbox: qcom: Convert APCS IPC driver to use regmap
KVM/SVM: Allow direct access to MSR_IA32_SPEC_CTRL
KVM/VMX: Allow direct access to MSR_IA32_SPEC_CTRL
KVM/VMX: Emulate MSR_IA32_ARCH_CAPABILITIES
KVM/x86: Add IBPB support
KVM/x86: Update the reverse_cpuid list to include CPUID_7_EDX
pinctrl: remove include file from <linux/device.h>
firmware: dmi: handle missing DMI data gracefully
firmware: dmi_scan: Fix handling of empty DMI strings
firmware: dmi_scan: Drop dmi_initialized
firmware: dmi: Optimize dmi_matches
Revert "defer call to mem_cgroup_sk_alloc()"
soreuseport: fix mem leak in reuseport_add_sock()
net: qlge: use memmove instead of skb_copy_to_linear_data
net: qed: use correct strncpy() size
net: cxgb4: avoid memcpy beyond end of source buffer
cls_u32: add missing RCU annotation.
r8152: set rx mode early when linking on
...
Diffstat (limited to 'include/linux/buffer_head.h')
| -rw-r--r-- | include/linux/buffer_head.h | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h index 58a82f58e44e..894e5d125de6 100644 --- a/include/linux/buffer_head.h +++ b/include/linux/buffer_head.h @@ -81,11 +81,14 @@ struct buffer_head { /* * macro tricks to expand the set_buffer_foo(), clear_buffer_foo() * and buffer_foo() functions. + * To avoid reset buffer flags that are already set, because that causes + * a costly cache line transition, check the flag first. */ #define BUFFER_FNS(bit, name) \ static __always_inline void set_buffer_##name(struct buffer_head *bh) \ { \ - set_bit(BH_##bit, &(bh)->b_state); \ + if (!test_bit(BH_##bit, &(bh)->b_state)) \ + set_bit(BH_##bit, &(bh)->b_state); \ } \ static __always_inline void clear_buffer_##name(struct buffer_head *bh) \ { \ |