The patch titled Subject: percpu-refcount: sparse fixes has been added to the -mm tree. Its filename is generic-dynamic-per-cpu-refcounting-sparse-fixes.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Kent Overstreet <koverstreet@xxxxxxxxxx> Subject: percpu-refcount: sparse fixes Here's some more fixes, the percpu refcount code is now sparse clean for me. It's kind of ugly, but I'm not sure it's really any uglier than it was before. Seem reasonable? Signed-off-by: Kent Overstreet <koverstreet@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/percpu-refcount.h | 2 - lib/percpu-refcount.c | 51 +++++++++++++++--------------- 2 files changed, 28 insertions(+), 25 deletions(-) diff -puN include/linux/percpu-refcount.h~generic-dynamic-per-cpu-refcounting-sparse-fixes include/linux/percpu-refcount.h --- a/include/linux/percpu-refcount.h~generic-dynamic-per-cpu-refcounting-sparse-fixes +++ a/include/linux/percpu-refcount.h @@ -7,7 +7,7 @@ struct percpu_ref { atomic64_t count; - unsigned __percpu *pcpu_count; + unsigned long pcpu_count; }; void percpu_ref_init(struct percpu_ref *ref); diff -puN lib/percpu-refcount.c~generic-dynamic-per-cpu-refcounting-sparse-fixes lib/percpu-refcount.c --- a/lib/percpu-refcount.c~generic-dynamic-per-cpu-refcounting-sparse-fixes +++ a/lib/percpu-refcount.c @@ -16,7 +16,7 @@ #define PCPU_REF_DYING 2 #define PCPU_REF_DEAD 3 -#define REF_STATUS(count) ((unsigned long) count & PCPU_STATUS_MASK) +#define REF_STATUS(count) (count & PCPU_STATUS_MASK) void percpu_ref_init(struct percpu_ref *ref) { @@ -27,47 +27,47 @@ void percpu_ref_init(struct percpu_ref * now <<= PCPU_STATUS_BITS; now |= PCPU_REF_NONE; - ref->pcpu_count = (void *) now; + ref->pcpu_count = now; } -static void percpu_ref_alloc(struct percpu_ref *ref, unsigned __user *pcpu_count) +static void percpu_ref_alloc(struct percpu_ref *ref, unsigned long pcpu_count) { - unsigned __percpu *new; - unsigned long last = (unsigned long) pcpu_count; - unsigned long now = jiffies; + unsigned long new, now = jiffies; now <<= PCPU_STATUS_BITS; now |= PCPU_REF_NONE; - if (now - last <= HZ << PCPU_STATUS_BITS) { + if (now - pcpu_count <= HZ << PCPU_STATUS_BITS) { rcu_read_unlock(); - new = alloc_percpu(unsigned); + new = (unsigned long) alloc_percpu(unsigned); rcu_read_lock(); if (!new) goto update_time; - BUG_ON(((unsigned long) new) & PCPU_STATUS_MASK); + BUG_ON(new & PCPU_STATUS_MASK); if (cmpxchg(&ref->pcpu_count, pcpu_count, new) != pcpu_count) - free_percpu(new); + free_percpu((void __percpu *) new); else pr_debug("created"); } else { -update_time: new = (void *) now; +update_time: new = now; cmpxchg(&ref->pcpu_count, pcpu_count, new); } } void __percpu_ref_get(struct percpu_ref *ref, bool alloc) { - unsigned __percpu *pcpu_count; + unsigned long pcpu_count; uint64_t v; - pcpu_count = rcu_dereference(ref->pcpu_count); + pcpu_count = ACCESS_ONCE(ref->pcpu_count); if (REF_STATUS(pcpu_count) == PCPU_REF_PTR) { - __this_cpu_inc(*pcpu_count); + /* for rcu - we're not using rcu_dereference() */ + smp_read_barrier_depends(); + __this_cpu_inc(*((unsigned __percpu *) pcpu_count)); } else { v = atomic64_add_return(1 + (1ULL << PCPU_COUNT_BITS), &ref->count); @@ -80,17 +80,19 @@ void __percpu_ref_get(struct percpu_ref int percpu_ref_put(struct percpu_ref *ref) { - unsigned __percpu *pcpu_count; + unsigned long pcpu_count; uint64_t v; int ret = 0; rcu_read_lock(); - pcpu_count = rcu_dereference(ref->pcpu_count); + pcpu_count = ACCESS_ONCE(ref->pcpu_count); switch (REF_STATUS(pcpu_count)) { case PCPU_REF_PTR: - __this_cpu_dec(*pcpu_count); + /* for rcu - we're not using rcu_dereference() */ + smp_read_barrier_depends(); + __this_cpu_dec(*((unsigned __percpu *) pcpu_count)); break; case PCPU_REF_NONE: case PCPU_REF_DYING: @@ -111,18 +113,19 @@ int percpu_ref_put(struct percpu_ref *re int percpu_ref_kill(struct percpu_ref *ref) { - unsigned __percpu *old, *new, *pcpu_count = ref->pcpu_count; - unsigned long status; + unsigned long old, new, status, pcpu_count; + + pcpu_count = ACCESS_ONCE(ref->pcpu_count); do { status = REF_STATUS(pcpu_count); switch (status) { case PCPU_REF_PTR: - new = (void *) PCPU_REF_DYING; + new = PCPU_REF_DYING; break; case PCPU_REF_NONE: - new = (void *) PCPU_REF_DEAD; + new = PCPU_REF_DEAD; break; case PCPU_REF_DYING: case PCPU_REF_DEAD: @@ -139,7 +142,7 @@ int percpu_ref_kill(struct percpu_ref *r synchronize_rcu(); for_each_possible_cpu(cpu) - count += *per_cpu_ptr(pcpu_count, cpu); + count += *per_cpu_ptr((unsigned __percpu *) pcpu_count, cpu); pr_debug("global %lli pcpu %i", atomic64_read(&ref->count) & PCPU_COUNT_MASK, @@ -148,9 +151,9 @@ int percpu_ref_kill(struct percpu_ref *r atomic64_add((int) count, &ref->count); smp_wmb(); /* Between setting global count and setting PCPU_REF_DEAD */ - ref->pcpu_count = (void *) PCPU_REF_DEAD; + ref->pcpu_count = PCPU_REF_DEAD; - free_percpu(pcpu_count); + free_percpu((unsigned __percpu *) pcpu_count); } return 1; _ Patches currently in -mm which might be from koverstreet@xxxxxxxxxx are jiffies-conversions-use-compile-time-constants-when-possible.patch mm-remove-old-aio-use_mm-comment.patch aio-remove-dead-code-from-aioh.patch gadget-remove-only-user-of-aio-retry.patch aio-remove-retry-based-aio.patch char-add-aio_readwrite-to-dev-nullzero.patch aio-kill-return-value-of-aio_complete.patch aio-kiocb_cancel.patch aio-kiocb_cancel-fix.patch aio-move-private-stuff-out-of-aioh.patch aio-dprintk-pr_debug.patch aio-do-fget-after-aio_get_req.patch aio-make-aio_put_req-lockless.patch aio-refcounting-cleanup.patch wait-add-wait_event_hrtimeout.patch wait-add-wait_event_hrtimeout-fix.patch aio-make-aio_read_evt-more-efficient-convert-to-hrtimers.patch aio-use-flush_dcache_page.patch aio-use-cancellation-list-lazily.patch aio-change-reqs_active-to-include-unreaped-completions.patch aio-kill-batch-allocation.patch aio-kill-struct-aio_ring_info.patch aio-give-shared-kioctx-fields-their-own-cachelines.patch aio-give-shared-kioctx-fields-their-own-cachelines-fix.patch aio-reqs_active-reqs_available.patch aio-percpu-reqs_available.patch generic-dynamic-per-cpu-refcounting.patch generic-dynamic-per-cpu-refcounting-fix.patch generic-dynamic-per-cpu-refcounting-fix-fix.patch generic-dynamic-per-cpu-refcounting-sparse-fixes.patch generic-dynamic-per-cpu-refcounting-sparse-fixes-fix.patch aio-percpu-ioctx-refcount.patch aio-use-xchg-instead-of-completion_lock.patch aio-dont-include-aioh-in-schedh.patch aio-dont-include-aioh-in-schedh-fix.patch aio-dont-include-aioh-in-schedh-fix-fix.patch aio-dont-include-aioh-in-schedh-fix-3.patch aio-kill-ki_key.patch aio-kill-ki_retry.patch aio-kill-ki_retry-fix.patch block-aio-batch-completion-for-bios-kiocbs.patch block-aio-batch-completion-for-bios-kiocbs-fix.patch block-aio-batch-completion-for-bios-kiocbs-fix-fix.patch block-aio-batch-completion-for-bios-kiocbs-fix-fix-fix.patch block-aio-batch-completion-for-bios-kiocbs-fix-fix-fix-fix.patch virtio-blk-convert-to-batch-completion.patch mtip32xx-convert-to-batch-completion.patch aio-smoosh-struct-kiocb.patch aio-smoosh-struct-kiocb-fix.patch aio-fix-aio_read_events_ring-types.patch aio-document-clarify-aio_read_events-and-shadow_tail.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html