diff mbox series

[v5,05/14] cache-tree: use ODB transaction around writing a tree

Message ID 83fa4a5f3a5c79fa814932c0705867ff16a584c7.1648616734.git.gitgitgadget@gmail.com (mailing list archive)
State Accepted
Commit 4d33e2ba6b9db6a28085b2ef7e46d30a981875ab
Headers show
Series core.fsyncmethod: add 'batch' mode for faster fsyncing of multiple objects | expand

Commit Message

Neeraj Singh (WINDOWS-SFS) March 30, 2022, 5:05 a.m. UTC
From: Neeraj Singh <neerajsi@microsoft.com>

Take advantage of the odb transaction infrastructure around writing the
cached tree to the object database.

Signed-off-by: Neeraj Singh <neerajsi@microsoft.com>
---
 cache-tree.c | 3 +++
 1 file changed, 3 insertions(+)

Comments

Junio C Hamano March 30, 2022, 5:46 p.m. UTC | #1
"Neeraj Singh via GitGitGadget" <gitgitgadget@gmail.com> writes:

> From: Neeraj Singh <neerajsi@microsoft.com>
>
> Take advantage of the odb transaction infrastructure around writing the
> cached tree to the object database.
>
> Signed-off-by: Neeraj Singh <neerajsi@microsoft.com>
> ---
>  cache-tree.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/cache-tree.c b/cache-tree.c
> index 6752f69d515..8c5e8822716 100644
> --- a/cache-tree.c
> +++ b/cache-tree.c
> @@ -3,6 +3,7 @@
>  #include "tree.h"
>  #include "tree-walk.h"
>  #include "cache-tree.h"
> +#include "bulk-checkin.h"
>  #include "object-store.h"
>  #include "replace-object.h"
>  #include "promisor-remote.h"
> @@ -474,8 +475,10 @@ int cache_tree_update(struct index_state *istate, int flags)
>  
>  	trace_performance_enter();
>  	trace2_region_enter("cache_tree", "update", the_repository);

There is no I/O in update_one() when the WRITE_TREE_DRY_RUN bit is
set, so we _could_ optimize the begin/end away with

	if (!(flags & WRITE_TREE_DRY_RUN))
		begin_odb_transaction()

> +	begin_odb_transaction();
>  	i = update_one(istate->cache_tree, istate->cache, istate->cache_nr,
>  		       "", 0, &skip, flags);
> +	end_odb_transaction();
>  	trace2_region_leave("cache_tree", "update", the_repository);
>  	trace_performance_leave("cache_tree_update");
>  	if (i < 0)

I do not know if that is worth it.  If we do not do any object
creation inside begin/end, we don't even create the temporary object
directory and there is nothing we need to do when we "unplug".  So
this would be fine as-is, but I may be overlooking something, so I
thought I'd mention it for completeness.

Thanks.
Neeraj Singh March 30, 2022, 7:04 p.m. UTC | #2
On Wed, Mar 30, 2022 at 10:47 AM Junio C Hamano <gitster@pobox.com> wrote:
>
> "Neeraj Singh via GitGitGadget" <gitgitgadget@gmail.com> writes:
>
> > From: Neeraj Singh <neerajsi@microsoft.com>
> >
> > Take advantage of the odb transaction infrastructure around writing the
> > cached tree to the object database.
> >
> > Signed-off-by: Neeraj Singh <neerajsi@microsoft.com>
> > ---
> >  cache-tree.c | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/cache-tree.c b/cache-tree.c
> > index 6752f69d515..8c5e8822716 100644
> > --- a/cache-tree.c
> > +++ b/cache-tree.c
> > @@ -3,6 +3,7 @@
> >  #include "tree.h"
> >  #include "tree-walk.h"
> >  #include "cache-tree.h"
> > +#include "bulk-checkin.h"
> >  #include "object-store.h"
> >  #include "replace-object.h"
> >  #include "promisor-remote.h"
> > @@ -474,8 +475,10 @@ int cache_tree_update(struct index_state *istate, int flags)
> >
> >       trace_performance_enter();
> >       trace2_region_enter("cache_tree", "update", the_repository);
>
> There is no I/O in update_one() when the WRITE_TREE_DRY_RUN bit is
> set, so we _could_ optimize the begin/end away with
>
>         if (!(flags & WRITE_TREE_DRY_RUN))
>                 begin_odb_transaction()
>
> > +     begin_odb_transaction();
> >       i = update_one(istate->cache_tree, istate->cache, istate->cache_nr,
> >                      "", 0, &skip, flags);
> > +     end_odb_transaction();
> >       trace2_region_leave("cache_tree", "update", the_repository);
> >       trace_performance_leave("cache_tree_update");
> >       if (i < 0)
>
> I do not know if that is worth it.  If we do not do any object
> creation inside begin/end, we don't even create the temporary object
> directory and there is nothing we need to do when we "unplug".  So
> this would be fine as-is, but I may be overlooking something, so I
> thought I'd mention it for completeness.
>

Yes, with the current series, beginning and ending a transaction will
just manipulate a few global variables in bulk-checkin.c unless there
is something real to flush.

Thanks,
Neeraj
diff mbox series

Patch

diff --git a/cache-tree.c b/cache-tree.c
index 6752f69d515..8c5e8822716 100644
--- a/cache-tree.c
+++ b/cache-tree.c
@@ -3,6 +3,7 @@ 
 #include "tree.h"
 #include "tree-walk.h"
 #include "cache-tree.h"
+#include "bulk-checkin.h"
 #include "object-store.h"
 #include "replace-object.h"
 #include "promisor-remote.h"
@@ -474,8 +475,10 @@  int cache_tree_update(struct index_state *istate, int flags)
 
 	trace_performance_enter();
 	trace2_region_enter("cache_tree", "update", the_repository);
+	begin_odb_transaction();
 	i = update_one(istate->cache_tree, istate->cache, istate->cache_nr,
 		       "", 0, &skip, flags);
+	end_odb_transaction();
 	trace2_region_leave("cache_tree", "update", the_repository);
 	trace_performance_leave("cache_tree_update");
 	if (i < 0)