Jan Kiszka wrote:
> Hi there,
>
> yea, I also want to join this endless pipe discussion! ;)
>
> We ran into troubles here due to large messages that should be sent via
> native pipes. Large means larger than the default message heap, the
> system heap, of the pipe subsystem so far. That raised the question why
> we should not provide some interface (and the required internal patches)
> to maintain per-pipe heaps. At least optional. This would allow to
> create pipe channels with even some megabyte space as we used them under
> RTAI.
>
> I would provide the required patches, but I'm not yet sure if we better
> extend rt_pipe_create with an additional parameter bufsize (0 = default,
> i.e. system heap, 0 > allocate per kmalloc or vmalloc) or if we add
> another function like rt_pipe_bufsize to allocate a dedicated heap after
> creation.
>
A patch says more than thousand words. ;)
As a first approach, I picked the second variant and implemented a new
function called rt_pipe_setpool. I also had to extend rt_pipe_alloc and
rt_pipe_free so that the right pool is used by them.
Note, the patch is yet untested and is also lacking documentation. It's
just intended to gain some feedback.
Jan
Index: skins/native/pipe.h
===================================================================
--- skins/native/pipe.h (Revision 165)
+++ skins/native/pipe.h (Arbeitskopie)
@@ -37,6 +37,8 @@
#ifdef __KERNEL__
+#include <nucleus/heap.h>
+
#define XENO_PIPE_MAGIC 0x55550202
typedef xnpipe_mh_t RT_PIPE_MSG;
@@ -57,6 +59,10 @@
RT_PIPE_MSG *buffer; /* !< Buffer used in byte stream mode. */
+ xnheap_t *bufpool; /* !< Current buffer pool. */
+
+ xnheap_t privpool; /* !< Private buffer pool. */
+
size_t fillsz; /* !< Bytes written to the buffer. */
u_long flushable; /* !< Flush request flag. */
@@ -87,6 +93,9 @@
const char *name,
int minor);
+int rt_pipe_setpool(RT_PIPE *pipe,
+ size_t poolsize);
+
int rt_pipe_delete(RT_PIPE *pipe);
ssize_t rt_pipe_read(RT_PIPE *pipe,
@@ -113,9 +122,11 @@
size_t size,
int mode);
-RT_PIPE_MSG *rt_pipe_alloc(size_t size);
+RT_PIPE_MSG *rt_pipe_alloc(RT_PIPE *pipe,
+ size_t size);
-int rt_pipe_free(RT_PIPE_MSG *msg);
+int rt_pipe_free(RT_PIPE *pipe,
+ RT_PIPE_MSG *msg);
ssize_t rt_pipe_flush(RT_PIPE *pipe);
Index: skins/native/syscall.c
===================================================================
--- skins/native/syscall.c (Revision 165)
+++ skins/native/syscall.c (Arbeitskopie)
@@ -3332,7 +3332,7 @@
/* Zero-sized messages are allowed, so we still need to free the
message buffer even if no data copy took place. */
- rt_pipe_free(msg);
+ rt_pipe_free(pipe,msg);
return err;
}
@@ -3374,7 +3374,7 @@
if (!__xn_access_ok(curr,VERIFY_READ,__xn_reg_arg2(regs),size))
return -EFAULT;
- msg = rt_pipe_alloc(size);
+ msg = rt_pipe_alloc(pipe,size);
if (!msg)
return -ENOMEM;
@@ -3386,7 +3386,7 @@
if (err != size)
/* If the operation failed, we need to free the message buffer
by ourselves. */
- rt_pipe_free(msg);
+ rt_pipe_free(pipe,msg);
return err;
}
@@ -3436,7 +3436,7 @@
}
else
{
- msg = rt_pipe_alloc(size);
+ msg = rt_pipe_alloc(pipe,size);
if (!msg)
return -ENOMEM;
@@ -3449,7 +3449,7 @@
err = rt_pipe_stream(pipe,buf,size);
if (msg)
- rt_pipe_free(msg);
+ rt_pipe_free(pipe,msg);
return err;
}
Index: skins/native/pipe.c
===================================================================
--- skins/native/pipe.c (Revision 165)
+++ skins/native/pipe.c (Arbeitskopie)
@@ -50,8 +50,6 @@
#include <native/registry.h>
#include <native/pipe.h>
-static xnheap_t *__pipe_heap = &kheap;
-
static int __pipe_flush_apc;
static DECLARE_XNQUEUE(__pipe_flush_q);
@@ -83,6 +81,14 @@
#endif /* CONFIG_XENO_NATIVE_EXPORT_REGISTRY */
+static void __pipe_flush_pool (xnheap_t *heap,
+ void *poolmem,
+ u_long poolsize,
+ void *cookie)
+{
+ xnarch_sysfree(poolmem,poolsize);
+}
+
static inline ssize_t __pipe_flush (RT_PIPE *pipe)
{
@@ -122,8 +128,10 @@
size_t size,
void *cookie)
{
+ RT_PIPE *pipe = (RT_PIPE *)cookie;
+
/* Allocate memory for the incoming message. */
- return xnheap_alloc(__pipe_heap,size);
+ return xnheap_alloc(pipe->bufpool,size);
}
static int __pipe_output_handler (int bminor,
@@ -131,8 +139,10 @@
int retval,
void *cookie)
{
+ RT_PIPE *pipe = (RT_PIPE *)cookie;
+
/* Free memory from output/discarded message. */
- xnheap_free(__pipe_heap,mh);
+ xnheap_free(pipe->bufpool,mh);
return retval;
}
@@ -240,6 +250,7 @@
return -EPERM;
pipe->buffer = NULL;
+ pipe->bufpool = &kheap;
pipe->fillsz = 0;
pipe->flushable = 0;
pipe->handle = 0; /* i.e. (still) unregistered pipe. */
@@ -289,6 +300,38 @@
return err;
}
+int rt_pipe_setpool(RT_PIPE *pipe,
+ size_t poolsize)
+{
+ int err;
+ void *poolmem;
+
+ if (!xnpod_root_p())
+ return -EPERM;
+
+ if ((poolsize == 0) || (pipe->bufpool == &pipe->privpool))
+ return -EINVAL;
+
+ poolmem = xnarch_sysalloc(poolsize);
+
+ if (!poolmem)
+ return -ENOMEM;
+
+ err = xnheap_init(&pipe->privpool,
+ poolmem,
+ poolsize,
+ PAGE_SIZE); /* Use natural page size */
+ if (err)
+ {
+ xnarch_sysfree(poolmem,poolsize);
+ return err;
+ }
+
+ pipe->bufpool = &pipe->privpool;
+
+ return 0;
+}
+
/**
* @fn int rt_pipe_delete(RT_PIPE *pipe)
*
@@ -337,14 +380,15 @@
if (!pipe)
{
err = xeno_handle_error(pipe,XENO_PIPE_MAGIC,RT_PIPE);
- goto unlock_and_exit;
+ xnlock_put_irqrestore(&nklock,s);
+ return err;
}
if (__test_and_clear_bit(0,&pipe->flushable))
{
/* Purge data waiting for flush. */
removeq(&__pipe_flush_q,&pipe->link);
- rt_pipe_free(pipe->buffer);
+ rt_pipe_free(pipe,pipe->buffer);
}
err = xnpipe_disconnect(pipe->minor);
@@ -356,10 +400,11 @@
xeno_mark_deleted(pipe);
- unlock_and_exit:
-
xnlock_put_irqrestore(&nklock,s);
+ if (pipe->bufpool == &pipe->privpool)
+ xnheap_destroy(&pipe->privpool,__pipe_flush_pool,NULL);
+
return err;
}
@@ -572,7 +617,7 @@
/* Zero-sized messages are allowed, so we still need to free the
message buffer even if no data copy took place. */
- rt_pipe_free(msg);
+ rt_pipe_free(pipe,msg);
return nbytes;
}
@@ -767,7 +812,7 @@
/* Try flushing the streaming buffer in any case. */
return rt_pipe_send(pipe,NULL,0,mode);
- msg = rt_pipe_alloc(size);
+ msg = rt_pipe_alloc(pipe,size);
if (!msg)
return -ENOMEM;
@@ -779,7 +824,7 @@
if (nbytes != size)
/* If the operation failed, we need to free the message buffer
by ourselves. */
- rt_pipe_free(msg);
+ rt_pipe_free(pipe,msg);
return nbytes;
}
@@ -886,7 +931,7 @@
if (pipe->buffer == NULL)
{
- pipe->buffer = rt_pipe_alloc(CONFIG_XENO_OPT_NATIVE_PIPE_BUFSZ);
+ pipe->buffer = rt_pipe_alloc(pipe,CONFIG_XENO_OPT_NATIVE_PIPE_BUFSZ);
if (pipe->buffer == NULL)
{
@@ -984,7 +1029,7 @@
}
/**
- * @fn RT_PIPE_MSG *rt_pipe_alloc(size_t size)
+ * @fn RT_PIPE_MSG *rt_pipe_alloc(RT_PIPE *pipe,size_t size)
*
* @brief Allocate a message pipe buffer.
*
@@ -1010,10 +1055,11 @@
* Rescheduling: never.
*/
-RT_PIPE_MSG *rt_pipe_alloc (size_t size)
+RT_PIPE_MSG *rt_pipe_alloc (RT_PIPE *pipe,
+ size_t size)
{
- RT_PIPE_MSG *msg = (RT_PIPE_MSG *)xnheap_alloc(__pipe_heap,size + sizeof(RT_PIPE_MSG));
+ RT_PIPE_MSG *msg = (RT_PIPE_MSG *)xnheap_alloc(pipe->bufpool,size + sizeof(RT_PIPE_MSG));
if (msg)
{
@@ -1025,7 +1071,7 @@
}
/**
- * @fn int rt_pipe_free(RT_PIPE_MSG *msg)
+ * @fn int rt_pipe_free(RT_PIPE *pipe,RT_PIPE_MSG *msg)
*
* @brief Free a message pipe buffer.
*
@@ -1049,9 +1095,9 @@
* Rescheduling: never.
*/
-int rt_pipe_free (RT_PIPE_MSG *msg)
+int rt_pipe_free (RT_PIPE *pipe,RT_PIPE_MSG *msg)
{
- return xnheap_free(__pipe_heap,msg);
+ return xnheap_free(pipe->bufpool,msg);
}
/[EMAIL PROTECTED]/
Index: testsuite/klatency/latency-module.c
===================================================================
--- testsuite/klatency/latency-module.c (Revision 165)
+++ testsuite/klatency/latency-module.c (Arbeitskopie)
@@ -83,7 +83,7 @@
maxjitter = maxj;
avgjitter = sumj / sample_count;
- msg = rt_pipe_alloc(sizeof(struct latency_stat));
+ msg = rt_pipe_alloc(&pipe,sizeof(struct latency_stat));
if (!msg)
{
@@ -103,7 +103,7 @@
ourselves. */
if (rt_pipe_send(&pipe,msg,sizeof(*s),0) != sizeof(*s))
- rt_pipe_free(msg);
+ rt_pipe_free(&pipe,msg);
}
}
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