RepoMirrors/ceph
1
0
Fork 0
mirror of https://github.com/ceph/ceph synced 2025-02-19 00:47:49 +00:00
Code Issues Packages Projects Releases Wiki Activity

librbd: don't do readahead when m_readahead_pos reaching limit

Browse Source 
When m_readahead_pos reaches the limit, there's no need to call
_compute_readahead to calculate the readahead. Just return with no
readahead.

Signed-off-by: Zhiqiang Wang <zhiqiang.wang@intel.com>
This commit is contained in:
Zhiqiang Wang 2015-04-07 14:23:38 +08:00
parent 04fe26921f
commit b47a5499a0
1 changed files with 9 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
src/common/Readahead.cc
View File

@ -30,6 +30,10 @@ Readahead::extent_t Readahead::update(const vector<extent_t>& extents, uint64_t
for (vector<extent_t>::const_iterator p = extents.begin(); p != extents.end(); ++p) { for (vector<extent_t>::const_iterator p = extents.begin(); p != extents.end(); ++p) {
_observe_read(p->first, p->second); _observe_read(p->first, p->second);
} }
if (m_readahead_pos >= limit) {
m_lock.Unlock();
return extent_t(0, 0);
}
pair<uint64_t, uint64_t> extent = _compute_readahead(limit); pair<uint64_t, uint64_t> extent = _compute_readahead(limit);
m_lock.Unlock(); m_lock.Unlock();
return extent; return extent;
@ -38,6 +42,10 @@ Readahead::extent_t Readahead::update(const vector<extent_t>& extents, uint64_t
Readahead::extent_t Readahead::update(uint64_t offset, uint64_t length, uint64_t limit) { Readahead::extent_t Readahead::update(uint64_t offset, uint64_t length, uint64_t limit) {
m_lock.Lock(); m_lock.Lock();
_observe_read(offset, length); _observe_read(offset, length);
if (m_readahead_pos >= limit) {
m_lock.Unlock();
return extent_t(0, 0);
}
extent_t extent = _compute_readahead(limit); extent_t extent = _compute_readahead(limit);
m_lock.Unlock(); m_lock.Unlock();
return extent; return extent;
@ -52,6 +60,7 @@ void Readahead::_observe_read(uint64_t offset, uint64_t length) {
m_consec_read_bytes = 0; m_consec_read_bytes = 0;
m_readahead_trigger_pos = 0; m_readahead_trigger_pos = 0;
m_readahead_size = 0; m_readahead_size = 0;
m_readahead_pos = 0;
} }
m_last_pos = offset + length; m_last_pos = offset + length;
} }