mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-03 13:26:41 +07:00
a8b0ca17b8
The nmi parameter indicated if we could do wakeups from the current
context, if not, we would set some state and self-IPI and let the
resulting interrupt do the wakeup.
For the various event classes:
- hardware: nmi=0; PMI is in fact an NMI or we run irq_work_run from
the PMI-tail (ARM etc.)
- tracepoint: nmi=0; since tracepoint could be from NMI context.
- software: nmi=[0,1]; some, like the schedule thing cannot
perform wakeups, and hence need 0.
As one can see, there is very little nmi=1 usage, and the down-side of
not using it is that on some platforms some software events can have a
jiffy delay in wakeup (when arch_irq_work_raise isn't implemented).
The up-side however is that we can remove the nmi parameter and save a
bunch of conditionals in fast paths.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Michael Cree <mcree@orcon.net.nz>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Don Zickus <dzickus@redhat.com>
Link: http://lkml.kernel.org/n/tip-agjev8eu666tvknpb3iaj0fg@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
97 lines
2.3 KiB
C
97 lines
2.3 KiB
C
#ifndef _KERNEL_EVENTS_INTERNAL_H
|
|
#define _KERNEL_EVENTS_INTERNAL_H
|
|
|
|
#define RING_BUFFER_WRITABLE 0x01
|
|
|
|
struct ring_buffer {
|
|
atomic_t refcount;
|
|
struct rcu_head rcu_head;
|
|
#ifdef CONFIG_PERF_USE_VMALLOC
|
|
struct work_struct work;
|
|
int page_order; /* allocation order */
|
|
#endif
|
|
int nr_pages; /* nr of data pages */
|
|
int writable; /* are we writable */
|
|
|
|
atomic_t poll; /* POLL_ for wakeups */
|
|
|
|
local_t head; /* write position */
|
|
local_t nest; /* nested writers */
|
|
local_t events; /* event limit */
|
|
local_t wakeup; /* wakeup stamp */
|
|
local_t lost; /* nr records lost */
|
|
|
|
long watermark; /* wakeup watermark */
|
|
|
|
struct perf_event_mmap_page *user_page;
|
|
void *data_pages[0];
|
|
};
|
|
|
|
extern void rb_free(struct ring_buffer *rb);
|
|
extern struct ring_buffer *
|
|
rb_alloc(int nr_pages, long watermark, int cpu, int flags);
|
|
extern void perf_event_wakeup(struct perf_event *event);
|
|
|
|
extern void
|
|
perf_event_header__init_id(struct perf_event_header *header,
|
|
struct perf_sample_data *data,
|
|
struct perf_event *event);
|
|
extern void
|
|
perf_event__output_id_sample(struct perf_event *event,
|
|
struct perf_output_handle *handle,
|
|
struct perf_sample_data *sample);
|
|
|
|
extern struct page *
|
|
perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff);
|
|
|
|
#ifdef CONFIG_PERF_USE_VMALLOC
|
|
/*
|
|
* Back perf_mmap() with vmalloc memory.
|
|
*
|
|
* Required for architectures that have d-cache aliasing issues.
|
|
*/
|
|
|
|
static inline int page_order(struct ring_buffer *rb)
|
|
{
|
|
return rb->page_order;
|
|
}
|
|
|
|
#else
|
|
|
|
static inline int page_order(struct ring_buffer *rb)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
static unsigned long perf_data_size(struct ring_buffer *rb)
|
|
{
|
|
return rb->nr_pages << (PAGE_SHIFT + page_order(rb));
|
|
}
|
|
|
|
static inline void
|
|
__output_copy(struct perf_output_handle *handle,
|
|
const void *buf, unsigned int len)
|
|
{
|
|
do {
|
|
unsigned long size = min_t(unsigned long, handle->size, len);
|
|
|
|
memcpy(handle->addr, buf, size);
|
|
|
|
len -= size;
|
|
handle->addr += size;
|
|
buf += size;
|
|
handle->size -= size;
|
|
if (!handle->size) {
|
|
struct ring_buffer *rb = handle->rb;
|
|
|
|
handle->page++;
|
|
handle->page &= rb->nr_pages - 1;
|
|
handle->addr = rb->data_pages[handle->page];
|
|
handle->size = PAGE_SIZE << page_order(rb);
|
|
}
|
|
} while (len);
|
|
}
|
|
|
|
#endif /* _KERNEL_EVENTS_INTERNAL_H */
|