This is a note to let you know that I've just added the patch titled bcache: allocate meta data pages as compound pages to the 5.8-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: bcache-allocate-meta-data-pages-as-compound-pages.patch and it can be found in the queue-5.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 5fe48867856367142d91a82f2cbf7a57a24cbb70 Mon Sep 17 00:00:00 2001 From: Coly Li <colyli@xxxxxxx> Date: Sat, 25 Jul 2020 20:00:16 +0800 Subject: bcache: allocate meta data pages as compound pages From: Coly Li <colyli@xxxxxxx> commit 5fe48867856367142d91a82f2cbf7a57a24cbb70 upstream. There are some meta data of bcache are allocated by multiple pages, and they are used as bio bv_page for I/Os to the cache device. for example cache_set->uuids, cache->disk_buckets, journal_write->data, bset_tree->data. For such meta data memory, all the allocated pages should be treated as a single memory block. Then the memory management and underlying I/O code can treat them more clearly. This patch adds __GFP_COMP flag to all the location allocating >0 order pages for the above mentioned meta data. Then their pages are treated as compound pages now. Signed-off-by: Coly Li <colyli@xxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/md/bcache/bset.c | 2 +- drivers/md/bcache/btree.c | 2 +- drivers/md/bcache/journal.c | 4 ++-- drivers/md/bcache/super.c | 2 +- 4 files changed, 5 insertions(+), 5 deletions(-) --- a/drivers/md/bcache/bset.c +++ b/drivers/md/bcache/bset.c @@ -322,7 +322,7 @@ int bch_btree_keys_alloc(struct btree_ke b->page_order = page_order; - t->data = (void *) __get_free_pages(gfp, b->page_order); + t->data = (void *) __get_free_pages(__GFP_COMP|gfp, b->page_order); if (!t->data) goto err; --- a/drivers/md/bcache/btree.c +++ b/drivers/md/bcache/btree.c @@ -785,7 +785,7 @@ int bch_btree_cache_alloc(struct cache_s mutex_init(&c->verify_lock); c->verify_ondisk = (void *) - __get_free_pages(GFP_KERNEL, ilog2(bucket_pages(c))); + __get_free_pages(GFP_KERNEL|__GFP_COMP, ilog2(bucket_pages(c))); c->verify_data = mca_bucket_alloc(c, &ZERO_KEY, GFP_KERNEL); --- a/drivers/md/bcache/journal.c +++ b/drivers/md/bcache/journal.c @@ -999,8 +999,8 @@ int bch_journal_alloc(struct cache_set * j->w[1].c = c; if (!(init_fifo(&j->pin, JOURNAL_PIN, GFP_KERNEL)) || - !(j->w[0].data = (void *) __get_free_pages(GFP_KERNEL, JSET_BITS)) || - !(j->w[1].data = (void *) __get_free_pages(GFP_KERNEL, JSET_BITS))) + !(j->w[0].data = (void *) __get_free_pages(GFP_KERNEL|__GFP_COMP, JSET_BITS)) || + !(j->w[1].data = (void *) __get_free_pages(GFP_KERNEL|__GFP_COMP, JSET_BITS))) return -ENOMEM; return 0; --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -1776,7 +1776,7 @@ void bch_cache_set_unregister(struct cac } #define alloc_bucket_pages(gfp, c) \ - ((void *) __get_free_pages(__GFP_ZERO|gfp, ilog2(bucket_pages(c)))) + ((void *) __get_free_pages(__GFP_ZERO|__GFP_COMP|gfp, ilog2(bucket_pages(c)))) struct cache_set *bch_cache_set_alloc(struct cache_sb *sb) { Patches currently in stable-queue which might be from colyli@xxxxxxx are queue-5.8/bcache-fix-overflow-in-offset_to_stripe.patch queue-5.8/bcache-use-disk_-start-end-_io_acct-to-count-i-o-for-bcache-device.patch queue-5.8/bcache-avoid-nr_stripes-overflow-in-bcache_device_init.patch queue-5.8/bcache-fix-bio_-start-end-_io_acct-with-proper-device.patch queue-5.8/bcache-allocate-meta-data-pages-as-compound-pages.patch