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由 Yufen Yu 提交于
hulk inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I53R0H CVE: NA backport: openEuler-22.03-LTS ------------------------------------------------- In some scenario, likely spark-sql, almost all meta file's size is less then 2MB and applications read these smaller files in random mode. That means, it may issue multiple times random io to rotate disk, which can cause performance degradation. To improve the small files random read, we try to read the first 2MB into pagecache on the first time of read. Then it can avoid multiple random io. In fact, applications can call fadvise system with POSIX_FADV_WILLNEED to achieve this goal. But, some apps may cannot easily do that. So, we provide a new file flag FMODE_CTL_WILLNEED. Signed-off-by: NYufen Yu <yuyufen@huawei.com> Reviewed-by: NHou Tao <houtao1@huawei.com> Signed-off-by: NYang Yingliang <yangyingliang@huawei.com> Conflicts: include/linux/fs.h Value '0x40000000' has been used for flag FMODE_BUF_RASYNC. Signed-off-by: NZhihao Cheng <chengzhihao1@huawei.com> Reviewed-by: NZhang Yi <yi.zhang@huawei.com> Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
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