From: zwu.kernel@gmail.com Subject: [RFC v4+ hot_track 08/19] vfs: add aging function Date: Mon, 29 Oct 2012 12:30:50 +0800 Message-ID: <1351485061-12297-9-git-send-email-zwu.kernel@gmail.com> References: <1351485061-12297-1-git-send-email-zwu.kernel@gmail.com> Cc: linux-ext4@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org, linuxram@linux.vnet.ibm.com, viro@zeniv.linux.org.uk, david@fromorbit.com, tytso@mit.edu, cmm@us.ibm.com, wuzhy@linux.vnet.ibm.com, wenqing.lz@taobao.com To: linux-fsdevel@vger.kernel.org Return-path: In-Reply-To: <1351485061-12297-1-git-send-email-zwu.kernel@gmail.com> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org From: Zhi Yong Wu Signed-off-by: Zhi Yong Wu --- fs/hot_tracking.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++++ fs/hot_tracking.h | 6 +++++ 2 files changed, 62 insertions(+), 0 deletions(-) diff --git a/fs/hot_tracking.c b/fs/hot_tracking.c index 9245dd3..fff0038 100644 --- a/fs/hot_tracking.c +++ b/fs/hot_tracking.c @@ -397,6 +397,24 @@ static u32 hot_temp_calc(struct hot_freq_data *freq_data) return result; } +static bool hot_is_obsolete(struct hot_freq_data *freq_data) +{ + int ret = 0; + struct timespec ckt = current_kernel_time(); + + u64 cur_time = timespec_to_ns(&ckt); + u64 last_read_ns = + (cur_time - timespec_to_ns(&freq_data->last_read_time)); + u64 last_write_ns = + (cur_time - timespec_to_ns(&freq_data->last_write_time)); + u64 kick_ns = TIME_TO_KICK * NSEC_PER_SEC; + + if ((last_read_ns > kick_ns) && (last_write_ns > kick_ns)) + ret = 1; + + return ret; +} + /* * Calculate a new temperature and, if necessary, * move the list_head corresponding to this inode or range @@ -463,6 +481,44 @@ static void hot_map_array_update(struct hot_freq_data *freq_data, } } +/* Update temperatures for each range item for aging purposes */ +static void hot_range_update(struct hot_inode_item *he, + struct hot_info *root) +{ + struct hot_range_item *hr_nodes[8]; + u32 start = 0; + bool obsolete; + int i, n; + + while (1) { + spin_lock(&he->lock); + n = radix_tree_gang_lookup(&he->hot_range_tree, + (void **)hr_nodes, start, + ARRAY_SIZE(hr_nodes)); + if (!n) { + spin_unlock(&he->lock); + break; + } + spin_unlock(&he->lock); + + start = hr_nodes[n - 1]->start + 1; + for (i = 0; i < n; i++) { + kref_get(&hr_nodes[i]->hot_range.refs); + hot_map_array_update( + &hr_nodes[i]->hot_range.hot_freq_data, root); + + spin_lock(&hr_nodes[i]->hot_range.lock); + obsolete = hot_is_obsolete( + &hr_nodes[i]->hot_range.hot_freq_data); + spin_unlock(&hr_nodes[i]->hot_range.lock); + + hot_range_item_put(hr_nodes[i]); + if (obsolete) + hot_range_item_put(hr_nodes[i]); + } + } +} + /* * Initialize inode and range map arrays. */ diff --git a/fs/hot_tracking.h b/fs/hot_tracking.h index 196b894..f5ec05a 100644 --- a/fs/hot_tracking.h +++ b/fs/hot_tracking.h @@ -26,6 +26,12 @@ #define FREQ_POWER 4 +/* + * time to quit keeping track of + * tracking data (seconds) + */ +#define TIME_TO_KICK 300 + /* NRR/NRW heat unit = 2^X accesses */ #define NRR_MULTIPLIER_POWER 20 /* NRR - number of reads since mount */ #define NRR_COEFF_POWER 0 -- 1.7.6.5