patch, 3 parts"Improving the `git add -p` interface" project

diff --git a/SoC-2012-Ideas.md b/SoC-2012-Ideas.md
index 29a374a..145b379 100644
--- a/SoC-2012-Ideas.md
+++ b/SoC-2012-Ideas.md
@@ -68,3 +68,34 @@ work to be done:
    and only accessed on demand.
 
 Proposed mentor: Jeff King
+
+Improving parallelism in various commands
+-----------------------------------------
+
+Git is mostly written single-threaded, with a few commands having
+bolted-on extensions to support parallel operation (notably git-grep,
+git-pack-objects and the core.preloadIndex feature).
+
+We have recently looked into some of these areas and made a few
+optimizations, but a big roadblock is that pack access is entirely
+single-threaded.  The project would consist of the following steps:
+
+ * In preparation (the half-step): identify commands that could
+   benefit from parallelism.  `git grep --cached` and `git grep
+   COMMIT` come to mind, but most likely also `git diff` and `git log
+   -p`.  You can probably find more.
+
+ * Rework the pack access mechanisms to allow the maximum possible
+   parallel access.
+
+ * Rework the commands found in the first step to use parallel pack
+   access if possible.  Along the way, document the improvements with
+   performance tests.
+
+The actual programming must be done in C using pthreads for obvious
+reasons.  At the very least you should not be scared of low-level
+programming.  Prior experience and access to one or more multi-core
+computers is a plus.
+
+Proposed by: Thomas Rast
+Possible mentor(s): Thomas Rast

diff --git a/SoC-2012-Ideas.md b/SoC-2012-Ideas.md
index 145b379..59d1baf 100644
--- a/SoC-2012-Ideas.md
+++ b/SoC-2012-Ideas.md
@@ -99,3 +99,44 @@ computers is a plus.
 
 Proposed by: Thomas Rast
 Possible mentor(s): Thomas Rast
+
+Designing a faster index format
+-------------------------------
+
+Git is pretty slow when managing huge repositories in terms of files
+in any given tree, as it needs to rewrite the index (in full) on
+pretty much every operation.  For example, even though _logically_
+`git add already_tracked_file` only changes a single blob SHA-1 in the
+index, Git will verify index correctness during loading and recompute
+the new hash during writing _over the whole index_.  It thus ends up
+spending a large amount of time simply on hashing the index.
+
+A carefully designed index format could help in several ways.  (For the
+complexity estimates below, let n be the number of index entries or
+the size of the index, which is roughly the same.)
+
+ * The work needed for something as simple as entering a new blob into
+   the index, which is possibly the most common operation in git
+   (think `git add -p` etc.) should be at most log(n).
+
+ * The work needed for a more complex operation that changes the
+   number of index entries will have to be larger unless we get into
+   database land.  However the amount of data that we SHA-1 over
+   should still be log(n).
+
+ * It may be possible to store the cache-tree data directly as part of
+   the index, always keeping it valid, and using that to validate
+   index consistency throughout.  If so, this would be a big boost to
+   other git operations that currently suffer from frequent cache-tree
+   invalidation.
+
+Note that there are other criteria than speed: the format should also
+be as easy to parse as possible, so as to simplify work for the other
+.git-reading programs (such as jgit and libgit2).  For the same
+reason, you will also have to show a significant speed boost as
+otherwise the break in compatibility is not worth the fallout.
+
+The programming work will be in C, as it replaces a core part of git.
+
+Proposed by: Thomas Rast
+Possible mentor(s): Thomas Rast

diff --git a/SoC-2012-Ideas.md b/SoC-2012-Ideas.md
index 59d1baf..b2cc475 100644
--- a/SoC-2012-Ideas.md
+++ b/SoC-2012-Ideas.md
@@ -140,3 +140,44 @@ The programming work will be in C, as it replaces a core part of git.
 
 Proposed by: Thomas Rast
 Possible mentor(s): Thomas Rast
+
+Improving the `git add -p` interface
+------------------------------------
+
+The interface behind `git {add|commit|stash|reset} {-p|-i}` is shared
+and called `git-add--interactive.perl`.    This project would mostly
+focus on the `--patch` side, as that seems to be much more widely
+used; however, improvements to `--interactive` would probably also be
+welcome.
+
+The `--patch` interface suffers from some design flaws caused largely
+by how the script grew:
+
+ * Application is not atomic: hitting Ctrl-C midway through patching
+   may still touch files.
+
+ * The terminal/line-based interface becomes a problem if diff hunks
+   are too long to fit in your terminal.
+
+ * Cannot go back and forth between files.
+
+ * Cannot reverse the direction of the patch.
+
+ * Cannot look at the diff in word-diff mode (and apply it normally).
+
+Due to the current design it is also pretty hard to add these features
+without adding to the mess.  Thus the project consists of:
+
+ * Come up with more ideas for features/improvements and discuss them
+   with users.
+
+ * Cleanly redesigning the main interface loop to allow for the above
+   features.
+
+ * Implement the new features.
+
+As the existing code is written in Perl, that is what you will use for
+this project.
+
+Proposed by: Thomas Rast
+Possible mentor(s): Thomas Rast