Never saw a profile of bset_search_tree() where it wasn't bottlenecked
on memory until I got my new Haswell machine, but when I tried it there
it was suddenly burning 20% of the cpu in the inner loop on shrd...
Turns out, the version of shrd that takes 64 bit operands has a 9 cycle
latency. hah.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Trying to treat btree pointers and leaf node pointers the same way was a
mistake - going to start being more explicit about the type of
key/pointer we're dealing with. This is the first part of that
refactoring; this patch shouldn't change any actual behaviour.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Couple changes:
* Consolidate bch_check_keys() and bch_check_key_order(), and move the
checks that only check_key_order() could do to bch_btree_iter_next().
* Get rid of CONFIG_BCACHE_EDEBUG - now, all that code is compiled in
when CONFIG_BCACHE_DEBUG is enabled, and there's now a sysfs file to
flip on the EDEBUG checks at runtime.
* Dropped an old not terribly useful check in rw_unlock(), and
refactored/improved a some of the other debug code.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Previously, bch_ptr_bad() could return false when there was a pointer to
a nonexistant device... it only filtered out keys with PTR_CHECK_DEV
pointers.
This behaviour was intended for multiple cache device support; for that,
just because the device for one of the pointers has gone away doesn't
mean we want to filter out the rest of the pointers.
But we don't yet explicitly filter/check individual pointers, so without
that this behaviour was wrong - a corrupt bkey with a bad device pointer
could cause us to deref a bad pointer. Doh.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Now, the on disk data structures are in a header that can be exported to
userspace - and having them all centralized is nice too.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Lots of stuff has been open coding its own btree traversal - which is
generally pretty simple code, but there are a few subtleties.
This adds new new functions, bch_btree_map_nodes() and
bch_btree_map_keys(), which do the traversal for you. Everything that's
open coding btree traversal now (with the exception of garbage
collection) is slowly going to be converted to these two functions;
being able to write other code at a higher level of abstraction is a
big improvement w.r.t. overall code quality.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
The flow of control in the old btree insertion code was rather -
backwards; we'd recurse down the btree (in btree_insert_recurse()), and
then if we needed to split the keys to be inserted into the parent node
would be effectively returned up to btree_insert_recurse(), which would
notice there was more work to do and finish the insertion.
The main problem with this was that the full logic for btree insertion
could only be used by calling btree_insert_recurse; if you'd gotten to a
btree leaf some other way and had a key to insert, if it turned out that
node needed to be split you were SOL.
This inverts the flow of control so btree_insert_node() does _full_
btree insertion, including splitting - and takes a (leaf) btree node to
insert into as a parameter.
This means we can now _correctly_ handle cache misses - for cache
misses, we need to insert a fake "check" key into the btree when we
discover we have a cache miss - while we still have the btree locked.
Previously, if the btree node was full inserting a cache miss would just
fail.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
btree_sort_fixup() was overly clever, because it was trying to avoid
pulling a key off the btree iterator in more than one place.
This led to a really obscure bug where we'd break early from the loop in
btree_sort_fixup() if the current key overlapped with keys in more than
one older set, and the next key it overlapped with was zero size.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull block IO driver bits from Jens Axboe:
"As I mentioned in the core block pull request, due to real life
circumstances the driver pull request would be late. Now it looks
like -rc2 late... On the plus side, apart form the rsxx update, these
are all things that I could argue could go in later in the cycle as
they are fixes and not features. So even though things are late, it's
not ALL bad.
The pull request contains:
- Updates to bcache, all bug fixes, from Kent.
- A pile of drbd bug fixes (no big features this time!).
- xen blk front/back fixes.
- rsxx driver updates, some of them deferred form 3.10. So should be
well cooked by now"
* 'for-3.11/drivers' of git://git.kernel.dk/linux-block: (63 commits)
bcache: Allocation kthread fixes
bcache: Fix GC_SECTORS_USED() calculation
bcache: Journal replay fix
bcache: Shutdown fix
bcache: Fix a sysfs splat on shutdown
bcache: Advertise that flushes are supported
bcache: check for allocation failures
bcache: Fix a dumb race
bcache: Use standard utility code
bcache: Update email address
bcache: Delete fuzz tester
bcache: Document shrinker reserve better
bcache: FUA fixes
drbd: Allow online change of al-stripes and al-stripe-size
drbd: Constants should be UPPERCASE
drbd: Ignore the exit code of a fence-peer handler if it returns too late
drbd: Fix rcu_read_lock balance on error path
drbd: fix error return code in drbd_init()
drbd: Do not sleep inside rcu
bcache: Refresh usage docs
...
The old lazy sorting code was kind of hacky - rewrite in a way that
mathematically makes more sense; the idea is that the size of the sets
of keys in a btree node should increase by a more or less fixed ratio
from smallest to biggest.
Signed-off-by: Kent Overstreet <koverstreet@google.com>
Old gcc doesnt like the struct hack, and it is kind of ugly. So finish
off the work to convert pr_debug() statements to tracepoints, and delete
pkey()/pbtree().
Signed-off-by: Kent Overstreet <koverstreet@google.com>
m68k/allmodconfig:
drivers/md/bcache/bset.c: In function ‘bset_search_tree’:
drivers/md/bcache/bset.c:727: error: implicit declaration of function ‘prefetch’
drivers/md/bcache/btree.c: In function ‘bch_btree_node_get’:
drivers/md/bcache/btree.c:933: error: implicit declaration of function ‘prefetch’
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Kent Overstreet <koverstreet@google.com>
Took out some nested functions, and fixed some more checkpatch
complaints.
Signed-off-by: Kent Overstreet <koverstreet@google.com>
Cc: linux-bcache@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
config: make ARCH=i386 allmodconfig
All error/warnings:
drivers/md/bcache/bset.c: In function 'bch_ptr_bad':
>> drivers/md/bcache/bset.c:164:2: warning: format '%li' expects argument of type 'long int', but argument 4 has type 'size_t' [-Wformat]
--
drivers/md/bcache/debug.c: In function 'bch_pbtree':
>> drivers/md/bcache/debug.c:86:4: warning: format '%li' expects argument of type 'long int', but argument 4 has type 'size_t' [-Wformat]
--
drivers/md/bcache/btree.c: In function 'bch_btree_read_done':
>> drivers/md/bcache/btree.c:245:8: warning: format '%lu' expects argument of type 'long unsigned int', but argument 4 has type 'size_t' [-Wformat]
--
drivers/md/bcache/closure.o: In function `closure_debug_init':
>> (.init.text+0x0): multiple definition of `init_module'
>> drivers/md/bcache/super.o:super.c:(.init.text+0x0): first defined here
Signed-off-by: Kent Overstreet <koverstreet@google.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: linux-bcache@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Does writethrough and writeback caching, handles unclean shutdown, and
has a bunch of other nifty features motivated by real world usage.
See the wiki at http://bcache.evilpiepirate.org for more.
Signed-off-by: Kent Overstreet <koverstreet@google.com>
