Message ID | 1307419010-3390-1-git-send-email-tm@tao.ma |
---|---|
State | Not Applicable, archived |
Headers | show |
On Tue 07-06-11 11:56:50, Tao Ma wrote: > From: Tao Ma <boyu.mt@taobao.com> > > In journal checkpoint, we write the buffer and wait for its finish. > But in cfq, the async queue has a very low priority, and in our test, > if there are too many sync queues and every queue is filled up with > requests, and the process will hang waiting for the log space. > > So this patch tries to use WRITE_SYNC in __flush_batch so that the request will > be moved into sync queue and handled by cfq timely. We also use the new plug, > sot that all the WRITE_SYNC requests can be given as a whole when we unplug it. OK, makes sense to me. I'd like to merge the patch but I'd also like to keep compatibility with ext4 here so I'll wait for a while what Ted thinks about this change... Ted? Honza > > Cc: Jan Kara <jack@suse.cz> > Reported-by: Robin Dong <sanbai@taobao.com> > Signed-off-by: Tao Ma <boyu.mt@taobao.com> > --- > fs/jbd/checkpoint.c | 6 +++++- > 1 files changed, 5 insertions(+), 1 deletions(-) > > diff --git a/fs/jbd/checkpoint.c b/fs/jbd/checkpoint.c > index e4b87bc..a7ce053 100644 > --- a/fs/jbd/checkpoint.c > +++ b/fs/jbd/checkpoint.c > @@ -22,6 +22,7 @@ > #include <linux/jbd.h> > #include <linux/errno.h> > #include <linux/slab.h> > +#include <linux/blkdev.h> > > /* > * Unlink a buffer from a transaction checkpoint list. > @@ -253,9 +254,12 @@ static void > __flush_batch(journal_t *journal, struct buffer_head **bhs, int *batch_count) > { > int i; > + struct blk_plug plug; > > + blk_start_plug(&plug); > for (i = 0; i < *batch_count; i++) > - write_dirty_buffer(bhs[i], WRITE); > + write_dirty_buffer(bhs[i], WRITE_SYNC); > + blk_finish_plug(&plug); > > for (i = 0; i < *batch_count; i++) { > struct buffer_head *bh = bhs[i]; > -- > 1.7.4 >
On Tue 07-06-11 11:56:50, Tao Ma wrote: > From: Tao Ma <boyu.mt@taobao.com> > > In journal checkpoint, we write the buffer and wait for its finish. > But in cfq, the async queue has a very low priority, and in our test, > if there are too many sync queues and every queue is filled up with > requests, and the process will hang waiting for the log space. > > So this patch tries to use WRITE_SYNC in __flush_batch so that the request will > be moved into sync queue and handled by cfq timely. We also use the new plug, > sot that all the WRITE_SYNC requests can be given as a whole when we unplug it. > > Cc: Jan Kara <jack@suse.cz> > Reported-by: Robin Dong <sanbai@taobao.com> > Signed-off-by: Tao Ma <boyu.mt@taobao.com> OK, since Ted took ext4 patch, I took this one to my tree as well. Thanks for your work. Honza > --- > fs/jbd/checkpoint.c | 6 +++++- > 1 files changed, 5 insertions(+), 1 deletions(-) > > diff --git a/fs/jbd/checkpoint.c b/fs/jbd/checkpoint.c > index e4b87bc..a7ce053 100644 > --- a/fs/jbd/checkpoint.c > +++ b/fs/jbd/checkpoint.c > @@ -22,6 +22,7 @@ > #include <linux/jbd.h> > #include <linux/errno.h> > #include <linux/slab.h> > +#include <linux/blkdev.h> > > /* > * Unlink a buffer from a transaction checkpoint list. > @@ -253,9 +254,12 @@ static void > __flush_batch(journal_t *journal, struct buffer_head **bhs, int *batch_count) > { > int i; > + struct blk_plug plug; > > + blk_start_plug(&plug); > for (i = 0; i < *batch_count; i++) > - write_dirty_buffer(bhs[i], WRITE); > + write_dirty_buffer(bhs[i], WRITE_SYNC); > + blk_finish_plug(&plug); > > for (i = 0; i < *batch_count; i++) { > struct buffer_head *bh = bhs[i]; > -- > 1.7.4 >
diff --git a/fs/jbd/checkpoint.c b/fs/jbd/checkpoint.c index e4b87bc..a7ce053 100644 --- a/fs/jbd/checkpoint.c +++ b/fs/jbd/checkpoint.c @@ -22,6 +22,7 @@ #include <linux/jbd.h> #include <linux/errno.h> #include <linux/slab.h> +#include <linux/blkdev.h> /* * Unlink a buffer from a transaction checkpoint list. @@ -253,9 +254,12 @@ static void __flush_batch(journal_t *journal, struct buffer_head **bhs, int *batch_count) { int i; + struct blk_plug plug; + blk_start_plug(&plug); for (i = 0; i < *batch_count; i++) - write_dirty_buffer(bhs[i], WRITE); + write_dirty_buffer(bhs[i], WRITE_SYNC); + blk_finish_plug(&plug); for (i = 0; i < *batch_count; i++) { struct buffer_head *bh = bhs[i];