greg/stasis-aries-wal
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

clarified some comments

Browse source
This commit is contained in:
Sears Russell 2011-08-19 22:07:22 +00:00
parent 50ec28e806
commit 6e1ba8fe48
1 changed files with 9 additions and 5 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

14
src/stasis/bufferManager/concurrentBufferManager.c
View file

@ -99,18 +99,22 @@ static int chWriteBackPage_helper(stasis_buffer_manager_t* bm, pageid_t pageid,
// When we optimize for sequential writes, we try to make sure that // When we optimize for sequential writes, we try to make sure that
// write back only happens in a single thread. Therefore, there is // write back only happens in a single thread. Therefore, there is
// no reason to put dirty pages in the LRU, and lruFast will ignore // no reason to put dirty pages in the LRU, and lruFast will ignore
// dirty pages that are inserted into it. Since we may be making a dirty // dirty pages that are inserted into it.
// page become clean here, we remove the page from LRU, and put it
// back in. (There is no need to do this if the sequential // Since we may be making a dirty page become clean here, we remove
// optimizations are turned off...) // the page from LRU, and put it back in.
if(stasis_buffer_manager_hint_writes_are_sequential) if(stasis_buffer_manager_hint_writes_are_sequential)
// The removal sets the page's ref count. It does nothing else if
// the page is dirty.
ch->lru->remove(ch->lru, p); ch->lru->remove(ch->lru, p);
// write calls stasis_page_flushed(p); // write calls stasis_page_flushed(p);
ch->page_handle->write(ch->page_handle, p); ch->page_handle->write(ch->page_handle, p);
// Put the page back in LRU iff we just took it out.
if(stasis_buffer_manager_hint_writes_are_sequential) if(stasis_buffer_manager_hint_writes_are_sequential)
// Put the page back in LRU iff we just took it out / changed its
// ref count.
ch->lru->insert(ch->lru, p); ch->lru->insert(ch->lru, p);
p->needsFlush = 0; p->needsFlush = 0;