user/sven/linux.git/io_uring/alloc_cache.h, branch v6.1.97Linux Kernel
https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v6.1.972023-04-06T10:10:52Zio_uring: fix poll/netmsg alloc caches2023-04-06T10:10:52ZPavel Begunkovasml.silence@gmail.com2023-03-30T12:52:38Zurn:sha1:d67b3cdacac911958c6353f043fe98d42c84f5ad
commit fd30d1cdcc4ff405fc54765edf2e11b03f2ed4f3 upstream.
We increase cache->nr_cached when we free into the cache but don't
decrease when we take from it, so in some time we'll get an empty
cache with cache->nr_cached larger than IO_ALLOC_CACHE_MAX, that fails
io_alloc_cache_put() and effectively disables caching.
Fixes: 9b797a37c4bd8 ("io_uring: add abstraction around apoll cache")
Cc: stable@vger.kernel.org
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
io_uring: impose max limit on apoll cache2022-07-25T00:39:17ZJens Axboeaxboe@kernel.dk2022-07-07T20:20:54Zurn:sha1:9731bc9855dc169f27433fef3c4d0ff3496c512d
Caches like this tend to grow to the peak size, and then never get any
smaller. Impose a max limit on the size, to prevent it from growing too
big.
A somewhat randomly chosen 512 is the max size we'll allow the cache
to get. If a batch of frees come in and would bring it over that, we
simply start kfree'ing the surplus.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
io_uring: add abstraction around apoll cache2022-07-25T00:39:17ZJens Axboeaxboe@kernel.dk2022-07-07T20:16:20Zurn:sha1:9b797a37c4bd83b03cedcfbd15852b836f5e562c
In preparation for adding limits, and one more user, abstract out the
core bits of the allocation+free cache.
Signed-off-by: Jens Axboe <axboe@kernel.dk>