From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751689AbdFTLgo (ORCPT ); Tue, 20 Jun 2017 07:36:44 -0400 Received: from mx2.suse.de ([195.135.220.15]:54031 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750993AbdFTLgm (ORCPT ); Tue, 20 Jun 2017 07:36:42 -0400 From: Nikolay Borisov To: tj@kernel.org Cc: jbacik@fb.com, jack@suse.cz, linux-kernel@vger.kernel.org, hannes@cmpxchg.org, mgorman@techsingularity.net, Nikolay Borisov Subject: [PATCH 1/2] percpu_counter: Rename __percpu_counter_add to percpu_counter_add_batch Date: Tue, 20 Jun 2017 14:36:29 +0300 Message-Id: <1497958590-6639-1-git-send-email-nborisov@suse.com> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 252e0ba6b77d ("lib: percpu_counter variable batch") added a batched version of percpu_counter_add. However, one problem with this patch is the fact that it overloads the meaning of double underscore, which in kernel-land are taken to implicitly mean there is no preempt protection for the API. Currently, in both !SMP and SMP configs percpu_counter_add calls __percpu_counter_add which is preempt safe due to explicit calls to preempt_disable. This state of play creates the false sense that __percpu_counter_add is less SMP-safe than percpu_counter_add. They are both identical irrespective of CONFIG_SNMP value. The only difference is that the __ version takes a batch parameter. Make this a bit more explicit by just renaming __percpu_counter_add to percpu_counter_add_batch. Signed-off-by: Nikolay Borisov --- fs/btrfs/disk-io.c | 4 ++-- fs/btrfs/extent_io.c | 2 +- fs/btrfs/inode.c | 4 ++-- fs/xfs/xfs_mount.c | 4 ++-- include/linux/backing-dev.h | 2 +- include/linux/blk-cgroup.h | 6 +++--- include/linux/mman.h | 2 +- include/linux/percpu_counter.h | 7 ++++--- include/net/inet_frag.h | 4 ++-- lib/flex_proportions.c | 6 +++--- lib/percpu_counter.c | 4 ++-- 11 files changed, 23 insertions(+), 22 deletions(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 2eaa1b1db08d..9fc37d6641cd 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1255,7 +1255,7 @@ void clean_tree_block(struct btrfs_fs_info *fs_info, btrfs_assert_tree_locked(buf); if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) { - __percpu_counter_add(&fs_info->dirty_metadata_bytes, + percpu_counter_add_batch(&fs_info->dirty_metadata_bytes, -buf->len, fs_info->dirty_metadata_batch); /* ugh, clear_extent_buffer_dirty needs to lock the page */ @@ -4048,7 +4048,7 @@ void btrfs_mark_buffer_dirty(struct extent_buffer *buf) buf->start, transid, fs_info->generation); was_dirty = set_extent_buffer_dirty(buf); if (!was_dirty) - __percpu_counter_add(&fs_info->dirty_metadata_bytes, + percpu_counter_add_batch(&fs_info->dirty_metadata_bytes, buf->len, fs_info->dirty_metadata_batch); #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index d3619e010005..a1c303f27699 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -3597,7 +3597,7 @@ lock_extent_buffer_for_io(struct extent_buffer *eb, set_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags); spin_unlock(&eb->refs_lock); btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN); - __percpu_counter_add(&fs_info->dirty_metadata_bytes, + percpu_counter_add_batch(&fs_info->dirty_metadata_bytes, -eb->len, fs_info->dirty_metadata_batch); ret = 1; diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index ef3c98c527c1..fa138217219e 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -1766,7 +1766,7 @@ static void btrfs_set_bit_hook(struct inode *inode, if (btrfs_is_testing(fs_info)) return; - __percpu_counter_add(&fs_info->delalloc_bytes, len, + percpu_counter_add_batch(&fs_info->delalloc_bytes, len, fs_info->delalloc_batch); spin_lock(&BTRFS_I(inode)->lock); BTRFS_I(inode)->delalloc_bytes += len; @@ -1840,7 +1840,7 @@ static void btrfs_clear_bit_hook(struct btrfs_inode *inode, &inode->vfs_inode, state->start, len); - __percpu_counter_add(&fs_info->delalloc_bytes, -len, + percpu_counter_add_batch(&fs_info->delalloc_bytes, -len, fs_info->delalloc_batch); spin_lock(&inode->lock); inode->delalloc_bytes -= len; diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c index 2eaf81859166..7147d4a8d207 100644 --- a/fs/xfs/xfs_mount.c +++ b/fs/xfs/xfs_mount.c @@ -1209,7 +1209,7 @@ xfs_mod_icount( struct xfs_mount *mp, int64_t delta) { - __percpu_counter_add(&mp->m_icount, delta, XFS_ICOUNT_BATCH); + percpu_counter_add_batch(&mp->m_icount, delta, XFS_ICOUNT_BATCH); if (__percpu_counter_compare(&mp->m_icount, 0, XFS_ICOUNT_BATCH) < 0) { ASSERT(0); percpu_counter_add(&mp->m_icount, -delta); @@ -1288,7 +1288,7 @@ xfs_mod_fdblocks( else batch = XFS_FDBLOCKS_BATCH; - __percpu_counter_add(&mp->m_fdblocks, delta, batch); + percpu_counter_add_batch(&mp->m_fdblocks, delta, batch); if (__percpu_counter_compare(&mp->m_fdblocks, mp->m_alloc_set_aside, XFS_FDBLOCKS_BATCH) >= 0) { /* we had space! */ diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index 557d84063934..ace73f96eb1e 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -66,7 +66,7 @@ static inline bool bdi_has_dirty_io(struct backing_dev_info *bdi) static inline void __add_wb_stat(struct bdi_writeback *wb, enum wb_stat_item item, s64 amount) { - __percpu_counter_add(&wb->stat[item], amount, WB_STAT_BATCH); + percpu_counter_add_batch(&wb->stat[item], amount, WB_STAT_BATCH); } static inline void __inc_wb_stat(struct bdi_writeback *wb, diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h index 01b62e7bac74..7104bea8dab1 100644 --- a/include/linux/blk-cgroup.h +++ b/include/linux/blk-cgroup.h @@ -518,7 +518,7 @@ static inline void blkg_stat_exit(struct blkg_stat *stat) */ static inline void blkg_stat_add(struct blkg_stat *stat, uint64_t val) { - __percpu_counter_add(&stat->cpu_cnt, val, BLKG_STAT_CPU_BATCH); + percpu_counter_add_batch(&stat->cpu_cnt, val, BLKG_STAT_CPU_BATCH); } /** @@ -597,14 +597,14 @@ static inline void blkg_rwstat_add(struct blkg_rwstat *rwstat, else cnt = &rwstat->cpu_cnt[BLKG_RWSTAT_READ]; - __percpu_counter_add(cnt, val, BLKG_STAT_CPU_BATCH); + percpu_counter_add_batch(cnt, val, BLKG_STAT_CPU_BATCH); if (op_is_sync(op)) cnt = &rwstat->cpu_cnt[BLKG_RWSTAT_SYNC]; else cnt = &rwstat->cpu_cnt[BLKG_RWSTAT_ASYNC]; - __percpu_counter_add(cnt, val, BLKG_STAT_CPU_BATCH); + percpu_counter_add_batch(cnt, val, BLKG_STAT_CPU_BATCH); } /** diff --git a/include/linux/mman.h b/include/linux/mman.h index 634c4c51fe3a..c8367041fafd 100644 --- a/include/linux/mman.h +++ b/include/linux/mman.h @@ -22,7 +22,7 @@ unsigned long vm_memory_committed(void); static inline void vm_acct_memory(long pages) { - __percpu_counter_add(&vm_committed_as, pages, vm_committed_as_batch); + percpu_counter_add_batch(&vm_committed_as, pages, vm_committed_as_batch); } static inline void vm_unacct_memory(long pages) diff --git a/include/linux/percpu_counter.h b/include/linux/percpu_counter.h index 84a109449610..ec065387f443 100644 --- a/include/linux/percpu_counter.h +++ b/include/linux/percpu_counter.h @@ -39,7 +39,8 @@ int __percpu_counter_init(struct percpu_counter *fbc, s64 amount, gfp_t gfp, void percpu_counter_destroy(struct percpu_counter *fbc); void percpu_counter_set(struct percpu_counter *fbc, s64 amount); -void __percpu_counter_add(struct percpu_counter *fbc, s64 amount, s32 batch); +void percpu_counter_add_batch(struct percpu_counter *fbc, s64 amount, + s32 batch); s64 __percpu_counter_sum(struct percpu_counter *fbc); int __percpu_counter_compare(struct percpu_counter *fbc, s64 rhs, s32 batch); @@ -50,7 +51,7 @@ static inline int percpu_counter_compare(struct percpu_counter *fbc, s64 rhs) static inline void percpu_counter_add(struct percpu_counter *fbc, s64 amount) { - __percpu_counter_add(fbc, amount, percpu_counter_batch); + percpu_counter_add_batch(fbc, amount, percpu_counter_batch); } static inline s64 percpu_counter_sum_positive(struct percpu_counter *fbc) @@ -136,7 +137,7 @@ percpu_counter_add(struct percpu_counter *fbc, s64 amount) } static inline void -__percpu_counter_add(struct percpu_counter *fbc, s64 amount, s32 batch) +percpu_counter_add_batch(struct percpu_counter *fbc, s64 amount, s32 batch) { percpu_counter_add(fbc, amount); } diff --git a/include/net/inet_frag.h b/include/net/inet_frag.h index 5894730ec82a..5932e6de8fc0 100644 --- a/include/net/inet_frag.h +++ b/include/net/inet_frag.h @@ -154,12 +154,12 @@ static inline int frag_mem_limit(struct netns_frags *nf) static inline void sub_frag_mem_limit(struct netns_frags *nf, int i) { - __percpu_counter_add(&nf->mem, -i, frag_percpu_counter_batch); + percpu_counter_add_batch(&nf->mem, -i, frag_percpu_counter_batch); } static inline void add_frag_mem_limit(struct netns_frags *nf, int i) { - __percpu_counter_add(&nf->mem, i, frag_percpu_counter_batch); + percpu_counter_add_batch(&nf->mem, i, frag_percpu_counter_batch); } static inline unsigned int sum_frag_mem_limit(struct netns_frags *nf) diff --git a/lib/flex_proportions.c b/lib/flex_proportions.c index a71cf1bdd4c9..2cc1f94e03a1 100644 --- a/lib/flex_proportions.c +++ b/lib/flex_proportions.c @@ -207,7 +207,7 @@ static void fprop_reflect_period_percpu(struct fprop_global *p, if (val < (nr_cpu_ids * PROP_BATCH)) val = percpu_counter_sum(&pl->events); - __percpu_counter_add(&pl->events, + percpu_counter_add_batch(&pl->events, -val + (val >> (period-pl->period)), PROP_BATCH); } else percpu_counter_set(&pl->events, 0); @@ -219,7 +219,7 @@ static void fprop_reflect_period_percpu(struct fprop_global *p, void __fprop_inc_percpu(struct fprop_global *p, struct fprop_local_percpu *pl) { fprop_reflect_period_percpu(p, pl); - __percpu_counter_add(&pl->events, 1, PROP_BATCH); + percpu_counter_add_batch(&pl->events, 1, PROP_BATCH); percpu_counter_add(&p->events, 1); } @@ -267,6 +267,6 @@ void __fprop_inc_percpu_max(struct fprop_global *p, return; } else fprop_reflect_period_percpu(p, pl); - __percpu_counter_add(&pl->events, 1, PROP_BATCH); + percpu_counter_add_batch(&pl->events, 1, PROP_BATCH); percpu_counter_add(&p->events, 1); } diff --git a/lib/percpu_counter.c b/lib/percpu_counter.c index 9c21000df0b5..8ee7e5ec21be 100644 --- a/lib/percpu_counter.c +++ b/lib/percpu_counter.c @@ -72,7 +72,7 @@ void percpu_counter_set(struct percpu_counter *fbc, s64 amount) } EXPORT_SYMBOL(percpu_counter_set); -void __percpu_counter_add(struct percpu_counter *fbc, s64 amount, s32 batch) +void percpu_counter_add_batch(struct percpu_counter *fbc, s64 amount, s32 batch) { s64 count; @@ -89,7 +89,7 @@ void __percpu_counter_add(struct percpu_counter *fbc, s64 amount, s32 batch) } preempt_enable(); } -EXPORT_SYMBOL(__percpu_counter_add); +EXPORT_SYMBOL(percpu_counter_add_batch); /* * Add up all the per-cpu counts, return the result. This is a more accurate -- 2.7.4