timer API transition for kernel 4.15
[lttng-modules.git] / lib / ringbuffer / ring_buffer_frontend.c
index 3d2e400dc437ae0cbe66cb299021c6cb8483b53c..abd975762eed6dbe40d4dbbf21f0de279b2aa051 100644 (file)
@@ -54,6 +54,7 @@
 #include <linux/delay.h>
 #include <linux/module.h>
 #include <linux/percpu.h>
+#include <asm/cacheflush.h>
 
 #include <wrapper/ringbuffer/config.h>
 #include <wrapper/ringbuffer/backend.h>
@@ -64,6 +65,7 @@
 #include <wrapper/kref.h>
 #include <wrapper/percpu-defs.h>
 #include <wrapper/timer.h>
+#include <wrapper/vmalloc.h>
 
 /*
  * Internal structure representing offsets to use at a sub-buffer switch.
@@ -146,8 +148,8 @@ void lib_ring_buffer_free(struct lib_ring_buffer *buf)
        struct channel *chan = buf->backend.chan;
 
        lib_ring_buffer_print_errors(chan, buf, buf->backend.cpu);
-       kfree(buf->commit_hot);
-       kfree(buf->commit_cold);
+       lttng_kvfree(buf->commit_hot);
+       lttng_kvfree(buf->commit_cold);
 
        lib_ring_buffer_backend_free(&buf->backend);
 }
@@ -244,7 +246,7 @@ int lib_ring_buffer_create(struct lib_ring_buffer *buf,
                return ret;
 
        buf->commit_hot =
-               kzalloc_node(ALIGN(sizeof(*buf->commit_hot)
+               lttng_kvzalloc_node(ALIGN(sizeof(*buf->commit_hot)
                                   * chan->backend.num_subbuf,
                                   1 << INTERNODE_CACHE_SHIFT),
                        GFP_KERNEL | __GFP_NOWARN,
@@ -255,7 +257,7 @@ int lib_ring_buffer_create(struct lib_ring_buffer *buf,
        }
 
        buf->commit_cold =
-               kzalloc_node(ALIGN(sizeof(*buf->commit_cold)
+               lttng_kvzalloc_node(ALIGN(sizeof(*buf->commit_cold)
                                   * chan->backend.num_subbuf,
                                   1 << INTERNODE_CACHE_SHIFT),
                        GFP_KERNEL | __GFP_NOWARN,
@@ -304,17 +306,17 @@ int lib_ring_buffer_create(struct lib_ring_buffer *buf,
 
        /* Error handling */
 free_init:
-       kfree(buf->commit_cold);
+       lttng_kvfree(buf->commit_cold);
 free_commit:
-       kfree(buf->commit_hot);
+       lttng_kvfree(buf->commit_hot);
 free_chanbuf:
        lib_ring_buffer_backend_free(&buf->backend);
        return ret;
 }
 
-static void switch_buffer_timer(unsigned long data)
+static void switch_buffer_timer(LTTNG_TIMER_FUNC_ARG_TYPE t)
 {
-       struct lib_ring_buffer *buf = (struct lib_ring_buffer *)data;
+       struct lib_ring_buffer *buf = lttng_from_timer(buf, t, switch_timer);
        struct channel *chan = buf->backend.chan;
        const struct lib_ring_buffer_config *config = &chan->backend.config;
 
@@ -339,22 +341,22 @@ static void lib_ring_buffer_start_switch_timer(struct lib_ring_buffer *buf)
 {
        struct channel *chan = buf->backend.chan;
        const struct lib_ring_buffer_config *config = &chan->backend.config;
+       unsigned int flags = 0;
 
        if (!chan->switch_timer_interval || buf->switch_timer_enabled)
                return;
 
        if (config->alloc == RING_BUFFER_ALLOC_PER_CPU)
-               lttng_init_timer_pinned(&buf->switch_timer);
-       else
-               init_timer(&buf->switch_timer);
+               flags = LTTNG_TIMER_PINNED;
 
-       buf->switch_timer.function = switch_buffer_timer;
+       lttng_timer_setup(&buf->switch_timer, switch_buffer_timer, flags, buf);
        buf->switch_timer.expires = jiffies + chan->switch_timer_interval;
-       buf->switch_timer.data = (unsigned long)buf;
+
        if (config->alloc == RING_BUFFER_ALLOC_PER_CPU)
                add_timer_on(&buf->switch_timer, buf->backend.cpu);
        else
                add_timer(&buf->switch_timer);
+
        buf->switch_timer_enabled = 1;
 }
 
@@ -375,9 +377,9 @@ static void lib_ring_buffer_stop_switch_timer(struct lib_ring_buffer *buf)
 /*
  * Polling timer to check the channels for data.
  */
-static void read_buffer_timer(unsigned long data)
+static void read_buffer_timer(LTTNG_TIMER_FUNC_ARG_TYPE t)
 {
-       struct lib_ring_buffer *buf = (struct lib_ring_buffer *)data;
+       struct lib_ring_buffer *buf = lttng_from_timer(buf, t, read_timer);
        struct channel *chan = buf->backend.chan;
        const struct lib_ring_buffer_config *config = &chan->backend.config;
 
@@ -404,6 +406,7 @@ static void lib_ring_buffer_start_read_timer(struct lib_ring_buffer *buf)
 {
        struct channel *chan = buf->backend.chan;
        const struct lib_ring_buffer_config *config = &chan->backend.config;
+       unsigned int flags;
 
        if (config->wakeup != RING_BUFFER_WAKEUP_BY_TIMER
            || !chan->read_timer_interval
@@ -411,18 +414,16 @@ static void lib_ring_buffer_start_read_timer(struct lib_ring_buffer *buf)
                return;
 
        if (config->alloc == RING_BUFFER_ALLOC_PER_CPU)
-               lttng_init_timer_pinned(&buf->read_timer);
-       else
-               init_timer(&buf->read_timer);
+               flags = LTTNG_TIMER_PINNED;
 
-       buf->read_timer.function = read_buffer_timer;
+       lttng_timer_setup(&buf->read_timer, read_buffer_timer, flags, buf);
        buf->read_timer.expires = jiffies + chan->read_timer_interval;
-       buf->read_timer.data = (unsigned long)buf;
 
        if (config->alloc == RING_BUFFER_ALLOC_PER_CPU)
                add_timer_on(&buf->read_timer, buf->backend.cpu);
        else
                add_timer(&buf->read_timer);
+
        buf->read_timer_enabled = 1;
 }
 
@@ -1180,6 +1181,47 @@ void lib_ring_buffer_move_consumer(struct lib_ring_buffer *buf,
 }
 EXPORT_SYMBOL_GPL(lib_ring_buffer_move_consumer);
 
+#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
+static void lib_ring_buffer_flush_read_subbuf_dcache(
+               const struct lib_ring_buffer_config *config,
+               struct channel *chan,
+               struct lib_ring_buffer *buf)
+{
+       struct lib_ring_buffer_backend_pages *pages;
+       unsigned long sb_bindex, id, i, nr_pages;
+
+       if (config->output != RING_BUFFER_MMAP)
+               return;
+
+       /*
+        * Architectures with caches aliased on virtual addresses may
+        * use different cache lines for the linear mapping vs
+        * user-space memory mapping. Given that the ring buffer is
+        * based on the kernel linear mapping, aligning it with the
+        * user-space mapping is not straightforward, and would require
+        * extra TLB entries. Therefore, simply flush the dcache for the
+        * entire sub-buffer before reading it.
+        */
+       id = buf->backend.buf_rsb.id;
+       sb_bindex = subbuffer_id_get_index(config, id);
+       pages = buf->backend.array[sb_bindex];
+       nr_pages = buf->backend.num_pages_per_subbuf;
+       for (i = 0; i < nr_pages; i++) {
+               struct lib_ring_buffer_backend_page *backend_page;
+
+               backend_page = &pages->p[i];
+               flush_dcache_page(pfn_to_page(backend_page->pfn));
+       }
+}
+#else
+static void lib_ring_buffer_flush_read_subbuf_dcache(
+               const struct lib_ring_buffer_config *config,
+               struct channel *chan,
+               struct lib_ring_buffer *buf)
+{
+}
+#endif
+
 /**
  * lib_ring_buffer_get_subbuf - get exclusive access to subbuffer for reading
  * @buf: ring buffer
@@ -1322,6 +1364,8 @@ retry:
        buf->get_subbuf_consumed = consumed;
        buf->get_subbuf = 1;
 
+       lib_ring_buffer_flush_read_subbuf_dcache(config, chan, buf);
+
        return 0;
 
 nodata:
@@ -1840,16 +1884,14 @@ static void _lib_ring_buffer_switch_remote(struct lib_ring_buffer *buf,
        }
 
        /*
-        * Taking lock on CPU hotplug to ensure two things: first, that the
+        * Disabling preemption ensures two things: first, that the
         * target cpu is not taken concurrently offline while we are within
-        * smp_call_function_single() (I don't trust that get_cpu() on the
-        * _local_ CPU actually inhibit CPU hotplug for the _remote_ CPU (to be
-        * confirmed)). Secondly, if it happens that the CPU is not online, our
-        * own call to lib_ring_buffer_switch_slow() needs to be protected from
-        * CPU hotplug handlers, which can also perform a remote subbuffer
-        * switch.
+        * smp_call_function_single(). Secondly, if it happens that the
+        * CPU is not online, our own call to lib_ring_buffer_switch_slow()
+        * needs to be protected from CPU hotplug handlers, which can
+        * also perform a remote subbuffer switch.
         */
-       get_online_cpus();
+       preempt_disable();
        param.buf = buf;
        param.mode = mode;
        ret = smp_call_function_single(buf->backend.cpu,
@@ -1858,7 +1900,7 @@ static void _lib_ring_buffer_switch_remote(struct lib_ring_buffer *buf,
                /* Remote CPU is offline, do it ourself. */
                lib_ring_buffer_switch_slow(buf, mode);
        }
-       put_online_cpus();
+       preempt_enable();
 }
 
 /* Switch sub-buffer if current sub-buffer is non-empty. */
@@ -1886,7 +1928,8 @@ static
 int lib_ring_buffer_try_reserve_slow(struct lib_ring_buffer *buf,
                                     struct channel *chan,
                                     struct switch_offsets *offsets,
-                                    struct lib_ring_buffer_ctx *ctx)
+                                    struct lib_ring_buffer_ctx *ctx,
+                                    void *client_ctx)
 {
        const struct lib_ring_buffer_config *config = &chan->backend.config;
        unsigned long reserve_commit_diff, offset_cmp;
@@ -1912,7 +1955,7 @@ retry:
                offsets->size = config->cb.record_header_size(config, chan,
                                                offsets->begin,
                                                &offsets->pre_header_padding,
-                                               ctx);
+                                               ctx, client_ctx);
                offsets->size +=
                        lib_ring_buffer_align(offsets->begin + offsets->size,
                                              ctx->largest_align)
@@ -1996,7 +2039,7 @@ retry:
                        config->cb.record_header_size(config, chan,
                                                offsets->begin,
                                                &offsets->pre_header_padding,
-                                               ctx);
+                                               ctx, client_ctx);
                offsets->size +=
                        lib_ring_buffer_align(offsets->begin + offsets->size,
                                              ctx->largest_align)
@@ -2060,7 +2103,8 @@ EXPORT_SYMBOL_GPL(lib_ring_buffer_lost_event_too_big);
  * -EIO for other errors, else returns 0.
  * It will take care of sub-buffer switching.
  */
-int lib_ring_buffer_reserve_slow(struct lib_ring_buffer_ctx *ctx)
+int lib_ring_buffer_reserve_slow(struct lib_ring_buffer_ctx *ctx,
+               void *client_ctx)
 {
        struct channel *chan = ctx->chan;
        const struct lib_ring_buffer_config *config = &chan->backend.config;
@@ -2073,7 +2117,7 @@ int lib_ring_buffer_reserve_slow(struct lib_ring_buffer_ctx *ctx)
 
        do {
                ret = lib_ring_buffer_try_reserve_slow(buf, chan, &offsets,
-                                                      ctx);
+                                                      ctx, client_ctx);
                if (unlikely(ret))
                        return ret;
        } while (unlikely(v_cmpxchg(config, &buf->offset, offsets.old,
This page took 0.02843 seconds and 4 git commands to generate.