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openmpi/ompi/mca/coll/tuned/coll_tuned_allreduce.c
Jeff Squyres e7ecd56bd2 This commit represents a bunch of work on a Mercurial side branch. As 
such, the commit message back to the master SVN repository is fairly
long.

= ORTE Job-Level Output Messages =

Add two new interfaces that should be used for all new code throughout
the ORTE and OMPI layers (we already make the search-and-replace on
the existing ORTE / OMPI layers):

 * orte_output(): (and corresponding friends ORTE_OUTPUT,
   orte_output_verbose, etc.)  This function sends the output directly
   to the HNP for processing as part of a job-specific output
   channel.  It supports all the same outputs as opal_output()
   (syslog, file, stdout, stderr), but for stdout/stderr, the output
   is sent to the HNP for processing and output.  More on this below.
 * orte_show_help(): This function is a drop-in-replacement for
   opal_show_help(), with two differences in functionality:
   1. the rendered text help message output is sent to the HNP for
      display (rather than outputting directly into the process' stderr
      stream)
   1. the HNP detects duplicate help messages and does not display them
      (so that you don't see the same error message N times, once from
      each of your N MPI processes); instead, it counts "new" instances
      of the help message and displays a message every ~5 seconds when
      there are new ones ("I got X new copies of the help message...")

opal_show_help and opal_output still exist, but they only output in
the current process.  The intent for the new orte_* functions is that
they can apply job-level intelligence to the output.  As such, we
recommend that all new ORTE and OMPI code use the new orte_*
functions, not thei opal_* functions.

=== New code ===

For ORTE and OMPI programmers, here's what you need to do differently
in new code:

 * Do not include opal/util/show_help.h or opal/util/output.h.
   Instead, include orte/util/output.h (this one header file has
   declarations for both the orte_output() series of functions and
   orte_show_help()).
 * Effectively s/opal_output/orte_output/gi throughout your code.
   Note that orte_output_open() takes a slightly different argument
   list (as a way to pass data to the filtering stream -- see below),
   so you if explicitly call opal_output_open(), you'll need to
   slightly adapt to the new signature of orte_output_open().
 * Literally s/opal_show_help/orte_show_help/.  The function signature
   is identical.

=== Notes ===

 * orte_output'ing to stream 0 will do similar to what
   opal_output'ing did, so leaving a hard-coded "0" as the first
   argument is safe.
 * For systems that do not use ORTE's RML or the HNP, the effect of
   orte_output_* and orte_show_help will be identical to their opal
   counterparts (the additional information passed to
   orte_output_open() will be lost!).  Indeed, the orte_* functions
   simply become trivial wrappers to their opal_* counterparts.  Note
   that we have not tested this; the code is simple but it is quite
   possible that we mucked something up.

= Filter Framework =

Messages sent view the new orte_* functions described above and
messages output via the IOF on the HNP will now optionally be passed
through a new "filter" framework before being output to
stdout/stderr.  The "filter" OPAL MCA framework is intended to allow
preprocessing to messages before they are sent to their final
destinations.  The first component that was written in the filter
framework was to create an XML stream, segregating all the messages
into different XML tags, etc.  This will allow 3rd party tools to read
the stdout/stderr from the HNP and be able to know exactly what each
text message is (e.g., a help message, another OMPI infrastructure
message, stdout from the user process, stderr from the user process,
etc.).

Filtering is not active by default.  Filter components must be
specifically requested, such as:

{{{
$ mpirun --mca filter xml ...
}}}

There can only be one filter component active.

= New MCA Parameters =

The new functionality described above introduces two new MCA
parameters:

 * '''orte_base_help_aggregate''': Defaults to 1 (true), meaning that
   help messages will be aggregated, as described above.  If set to 0,
   all help messages will be displayed, even if they are duplicates
   (i.e., the original behavior).
 * '''orte_base_show_output_recursions''': An MCA parameter to help
   debug one of the known issues, described below.  It is likely that
   this MCA parameter will disappear before v1.3 final.

= Known Issues =

 * The XML filter component is not complete.  The current output from
   this component is preliminary and not real XML.  A bit more work
   needs to be done to configure.m4 search for an appropriate XML
   library/link it in/use it at run time.
 * There are possible recursion loops in the orte_output() and
   orte_show_help() functions -- e.g., if RML send calls orte_output()
   or orte_show_help().  We have some ideas how to fix these, but
   figured that it was ok to commit before feature freeze with known
   issues.  The code currently contains sub-optimal workarounds so
   that this will not be a problem, but it would be good to actually
   solve the problem rather than have hackish workarounds before v1.3 final.

This commit was SVN r18434.
2008-05-13 20:00:55 +00:00

1032 строки
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Исходник Ответственный История

/*
* Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
* University Research and Technology
* Corporation. All rights reserved.
* Copyright (c) 2004-2006 The University of Tennessee and The University
* of Tennessee Research Foundation. All rights
* reserved.
* Copyright (c) 2004-2005 High Performance Computing Center Stuttgart,
* University of Stuttgart. All rights reserved.
* Copyright (c) 2004-2005 The Regents of the University of California.
* All rights reserved.
* $COPYRIGHT$
*
* Additional copyrights may follow
*
* $HEADER$
*/
#include "ompi_config.h"
#include "mpi.h"
#include "ompi/constants.h"
#include "ompi/datatype/datatype.h"
#include "ompi/communicator/communicator.h"
#include "ompi/mca/coll/coll.h"
#include "ompi/mca/coll/base/coll_tags.h"
#include "ompi/mca/pml/pml.h"
#include "ompi/op/op.h"
#include "coll_tuned.h"
#include "coll_tuned_topo.h"
#include "coll_tuned_util.h"
/*
* ompi_coll_tuned_allreduce_intra_nonoverlapping
*
* This function just calls a reduce followed by a broadcast
* both called functions are tuned but they complete sequentially,
* i.e. no additional overlapping
* meaning if the number of segments used is greater than the topo depth
* then once the first segment of data is fully 'reduced' it is not broadcast
* while the reduce continues (cost = cost-reduce + cost-bcast + decision x 3)
*
*/
int
ompi_coll_tuned_allreduce_intra_nonoverlapping(void *sbuf, void *rbuf, int count,
struct ompi_datatype_t *dtype,
struct ompi_op_t *op,
struct ompi_communicator_t *comm,
struct mca_coll_base_module_1_1_0_t *module)
{
int err;
int rank;
rank = ompi_comm_rank(comm);
ORTE_OUTPUT((ompi_coll_tuned_stream,"coll:tuned:allreduce_intra_nonoverlapping rank %d", rank));
/* Reduce to 0 and broadcast. */
if (MPI_IN_PLACE == sbuf) {
if (0 == ompi_comm_rank(comm)) {
err = comm->c_coll.coll_reduce (MPI_IN_PLACE, rbuf, count, dtype,
op, 0, comm, module);
} else {
err = comm->c_coll.coll_reduce (rbuf, NULL, count, dtype, op, 0,
comm, module);
}
} else {
err = comm->c_coll.coll_reduce (sbuf, rbuf, count, dtype, op, 0, comm, module);
}
if (MPI_SUCCESS != err) {
return err;
}
return comm->c_coll.coll_bcast (rbuf, count, dtype, 0, comm, module);
}
/*
* ompi_coll_tuned_allreduce_intra_recursivedoubling
*
* Function: Recursive doubling algorithm for allreduce operation
* Accepts: Same as MPI_Allreduce()
* Returns: MPI_SUCCESS or error code
*
* Description: Implements recursive doubling algorithm for allreduce.
* Original (non-segmented) implementation is used in MPICH-2
* for small and intermediate size messages.
* The algorithm preserves order of operations so it can
* be used both by commutative and non-commutative operations.
*
* Example on 7 nodes:
* Initial state
* # 0 1 2 3 4 5 6
* [0] [1] [2] [3] [4] [5] [6]
* Initial adjustment step for non-power of two nodes.
* old rank 1 3 5 6
* new rank 0 1 2 3
* [0+1] [2+3] [4+5] [6]
* Step 1
* old rank 1 3 5 6
* new rank 0 1 2 3
* [0+1+] [0+1+] [4+5+] [4+5+]
* [2+3+] [2+3+] [6 ] [6 ]
* Step 2
* old rank 1 3 5 6
* new rank 0 1 2 3
* [0+1+] [0+1+] [0+1+] [0+1+]
* [2+3+] [2+3+] [2+3+] [2+3+]
* [4+5+] [4+5+] [4+5+] [4+5+]
* [6 ] [6 ] [6 ] [6 ]
* Final adjustment step for non-power of two nodes
* # 0 1 2 3 4 5 6
* [0+1+] [0+1+] [0+1+] [0+1+] [0+1+] [0+1+] [0+1+]
* [2+3+] [2+3+] [2+3+] [2+3+] [2+3+] [2+3+] [2+3+]
* [4+5+] [4+5+] [4+5+] [4+5+] [4+5+] [4+5+] [4+5+]
* [6 ] [6 ] [6 ] [6 ] [6 ] [6 ] [6 ]
*
*/
int
ompi_coll_tuned_allreduce_intra_recursivedoubling(void *sbuf, void *rbuf,
int count,
struct ompi_datatype_t *dtype,
struct ompi_op_t *op,
struct ompi_communicator_t *comm,
struct mca_coll_base_module_1_1_0_t *module)
{
int ret, line;
int rank, size, adjsize, remote, distance;
int newrank, newremote, extra_ranks;
char *tmpsend = NULL, *tmprecv = NULL, *tmpswap = NULL, *inplacebuf = NULL;
ptrdiff_t true_lb, true_extent, lb, extent;
ompi_request_t *reqs[2] = {NULL, NULL};
size = ompi_comm_size(comm);
rank = ompi_comm_rank(comm);
ORTE_OUTPUT((ompi_coll_tuned_stream,
"coll:tuned:allreduce_intra_recursivedoubling rank %d", rank));
/* Special case for size == 1 */
if (1 == size) {
if (MPI_IN_PLACE != sbuf) {
ret = ompi_ddt_copy_content_same_ddt(dtype, count, (char*)rbuf, (char*)sbuf);
if (ret < 0) { line = __LINE__; goto error_hndl; }
}
return MPI_SUCCESS;
}
/* Allocate and initialize temporary send buffer */
ret = ompi_ddt_get_extent(dtype, &lb, &extent);
if (MPI_SUCCESS != ret) { line = __LINE__; goto error_hndl; }
ret = ompi_ddt_get_true_extent(dtype, &true_lb, &true_extent);
if (MPI_SUCCESS != ret) { line = __LINE__; goto error_hndl; }
inplacebuf = (char*) malloc(true_extent + (count - 1) * extent);
if (NULL == inplacebuf) { ret = -1; line = __LINE__; goto error_hndl; }
if (MPI_IN_PLACE == sbuf) {
ret = ompi_ddt_copy_content_same_ddt(dtype, count, inplacebuf, (char*)rbuf);
if (ret < 0) { line = __LINE__; goto error_hndl; }
} else {
ret = ompi_ddt_copy_content_same_ddt(dtype, count, inplacebuf, (char*)sbuf);
if (ret < 0) { line = __LINE__; goto error_hndl; }
}
tmpsend = (char*) inplacebuf;
tmprecv = (char*) rbuf;
/* Determine nearest power of two less than or equal to size */
for (adjsize = 0x1; adjsize <= size; adjsize <<= 1); adjsize = adjsize >> 1;
/* Handle non-power-of-two case:
- Even ranks less than 2 * extra_ranks send their data to (rank + 1), and
sets new rank to -1.
- Odd ranks less than 2 * extra_ranks receive data from (rank - 1),
apply appropriate operation, and set new rank to rank/2
- Everyone else sets rank to rank - extra_ranks
*/
extra_ranks = size - adjsize;
if (rank < (2 * extra_ranks)) {
if (0 == (rank % 2)) {
ret = MCA_PML_CALL(send(tmpsend, count, dtype, (rank + 1),
MCA_COLL_BASE_TAG_ALLREDUCE,
MCA_PML_BASE_SEND_STANDARD, comm));
if (MPI_SUCCESS != ret) { line = __LINE__; goto error_hndl; }
newrank = -1;
} else {
ret = MCA_PML_CALL(recv(tmprecv, count, dtype, (rank - 1),
MCA_COLL_BASE_TAG_ALLREDUCE, comm,
MPI_STATUS_IGNORE));
if (MPI_SUCCESS != ret) { line = __LINE__; goto error_hndl; }
/* tmpsend = tmprecv (op) tmpsend */
ompi_op_reduce(op, tmprecv, tmpsend, count, dtype);
newrank = rank >> 1;
}
} else {
newrank = rank - extra_ranks;
}
/* Communication/Computation loop
- Exchange message with remote node.
- Perform appropriate operation taking in account order of operations:
result = value (op) result
*/
for (distance = 0x1; distance < adjsize; distance <<=1) {
if (newrank < 0) break;
/* Determine remote node */
newremote = newrank ^ distance;
remote = (newremote < extra_ranks)?
(newremote * 2 + 1):(newremote + extra_ranks);
/* Exchange the data */
ret = MCA_PML_CALL(irecv(tmprecv, count, dtype, remote,
MCA_COLL_BASE_TAG_ALLREDUCE, comm, &reqs[0]));
if (MPI_SUCCESS != ret) { line = __LINE__; goto error_hndl; }
ret = MCA_PML_CALL(isend(tmpsend, count, dtype, remote,
MCA_COLL_BASE_TAG_ALLREDUCE,
MCA_PML_BASE_SEND_STANDARD, comm, &reqs[1]));
if (MPI_SUCCESS != ret) { line = __LINE__; goto error_hndl; }
ret = ompi_request_wait_all(2, reqs, MPI_STATUSES_IGNORE);
if (MPI_SUCCESS != ret) { line = __LINE__; goto error_hndl; }
/* Apply operation */
if (rank < remote) {
/* tmprecv = tmpsend (op) tmprecv */
ompi_op_reduce(op, tmpsend, tmprecv, count, dtype);
tmpswap = tmprecv;
tmprecv = tmpsend;
tmpsend = tmpswap;
} else {
/* tmpsend = tmprecv (op) tmpsend */
ompi_op_reduce(op, tmprecv, tmpsend, count, dtype);
}
}
/* Handle non-power-of-two case:
- Odd ranks less than 2 * extra_ranks send result from tmpsend to
(rank - 1)
- Even ranks less than 2 * extra_ranks receive result from (rank + 1)
*/
if (rank < (2 * extra_ranks)) {
if (0 == (rank % 2)) {
ret = MCA_PML_CALL(recv(rbuf, count, dtype, (rank + 1),
MCA_COLL_BASE_TAG_ALLREDUCE, comm,
MPI_STATUS_IGNORE));
if (MPI_SUCCESS != ret) { line = __LINE__; goto error_hndl; }
tmpsend = (char*)rbuf;
} else {
ret = MCA_PML_CALL(send(tmpsend, count, dtype, (rank - 1),
MCA_COLL_BASE_TAG_ALLREDUCE,
MCA_PML_BASE_SEND_STANDARD, comm));
if (MPI_SUCCESS != ret) { line = __LINE__; goto error_hndl; }
}
}
/* Ensure that the final result is in rbuf */
if (tmpsend != rbuf) {
ret = ompi_ddt_copy_content_same_ddt(dtype, count, (char*)rbuf, tmpsend);
if (ret < 0) { line = __LINE__; goto error_hndl; }
}
if (NULL != inplacebuf) free(inplacebuf);
return MPI_SUCCESS;
error_hndl:
ORTE_OUTPUT((ompi_coll_tuned_stream, "%s:%4d\tRank %d Error occurred %d\n",
__FILE__, line, rank, ret));
if (NULL != inplacebuf) free(inplacebuf);
return ret;
}
/*
* ompi_coll_tuned_allreduce_intra_ring
*
* Function: Ring algorithm for allreduce operation
* Accepts: Same as MPI_Allreduce()
* Returns: MPI_SUCCESS or error code
*
* Description: Implements ring algorithm for allreduce: the message is
* automatically segmented to segment of size M/N.
* Algorithm requires 2*N - 1 steps.
*
* Limitations: The algorithm DOES NOT preserve order of operations so it
* can be used only for commutative operations.
* In addition, algorithm cannot work if the total count is
* less than size.
* Example on 5 nodes:
* Initial state
* # 0 1 2 3 4
* [00] [10] [20] [30] [40]
* [01] [11] [21] [31] [41]
* [02] [12] [22] [32] [42]
* [03] [13] [23] [33] [43]
* [04] [14] [24] [34] [44]
*
* COMPUTATION PHASE
* Step 0: rank r sends block r to rank (r+1) and receives bloc (r-1)
* from rank (r-1) [with wraparound].
* # 0 1 2 3 4
* [00] [00+10] [20] [30] [40]
* [01] [11] [11+21] [31] [41]
* [02] [12] [22] [22+32] [42]
* [03] [13] [23] [33] [33+43]
* [44+04] [14] [24] [34] [44]
*
* Step 1: rank r sends block (r-1) to rank (r+1) and receives bloc
* (r-2) from rank (r-1) [with wraparound].
* # 0 1 2 3 4
* [00] [00+10] [01+10+20] [30] [40]
* [01] [11] [11+21] [11+21+31] [41]
* [02] [12] [22] [22+32] [22+32+42]
* [33+43+03] [13] [23] [33] [33+43]
* [44+04] [44+04+14] [24] [34] [44]
*
* Step 2: rank r sends block (r-2) to rank (r+1) and receives bloc
* (r-2) from rank (r-1) [with wraparound].
* # 0 1 2 3 4
* [00] [00+10] [01+10+20] [01+10+20+30] [40]
* [01] [11] [11+21] [11+21+31] [11+21+31+41]
* [22+32+42+02] [12] [22] [22+32] [22+32+42]
* [33+43+03] [33+43+03+13] [23] [33] [33+43]
* [44+04] [44+04+14] [44+04+14+24] [34] [44]
*
* Step 3: rank r sends block (r-3) to rank (r+1) and receives bloc
* (r-3) from rank (r-1) [with wraparound].
* # 0 1 2 3 4
* [00] [00+10] [01+10+20] [01+10+20+30] [FULL]
* [FULL] [11] [11+21] [11+21+31] [11+21+31+41]
* [22+32+42+02] [FULL] [22] [22+32] [22+32+42]
* [33+43+03] [33+43+03+13] [FULL] [33] [33+43]
* [44+04] [44+04+14] [44+04+14+24] [FULL] [44]
*
* DISTRIBUTION PHASE: ring ALLGATHER with ranks shifted by 1.
*
*/
int
ompi_coll_tuned_allreduce_intra_ring(void *sbuf, void *rbuf, int count,
struct ompi_datatype_t *dtype,
struct ompi_op_t *op,
struct ompi_communicator_t *comm,
struct mca_coll_base_module_1_1_0_t *module)
{
int ret, line;
int rank, size, k, recv_from, send_to;
int early_segcount, late_segcount, split_rank, max_segcount;
int block_count, inbi;
size_t typelng;
char *tmpsend = NULL, *tmprecv = NULL;
char *inbuf[2] = {NULL, NULL};
ptrdiff_t true_lb, true_extent, lb, extent;
ptrdiff_t block_offset, max_real_segsize;
ompi_request_t *reqs[2] = {NULL, NULL};
size = ompi_comm_size(comm);
rank = ompi_comm_rank(comm);
ORTE_OUTPUT((ompi_coll_tuned_stream,
"coll:tuned:allreduce_intra_ring rank %d, count %d", rank, count));
/* Special case for size == 1 */
if (1 == size) {
if (MPI_IN_PLACE != sbuf) {
ret = ompi_ddt_copy_content_same_ddt(dtype, count, (char*)rbuf, (char*)sbuf);
if (ret < 0) { line = __LINE__; goto error_hndl; }
}
return MPI_SUCCESS;
}
/* Special case for count less than size - use recursive doubling */
if (count < size) {
ORTE_OUTPUT((ompi_coll_tuned_stream, "coll:tuned:allreduce_ring rank %d/%d, count %d, switching to recursive doubling", rank, size, count));
return (ompi_coll_tuned_allreduce_intra_recursivedoubling(sbuf, rbuf,
count,
dtype, op,
comm, module));
}
/* Allocate and initialize temporary buffers */
ret = ompi_ddt_get_extent(dtype, &lb, &extent);
if (MPI_SUCCESS != ret) { line = __LINE__; goto error_hndl; }
ret = ompi_ddt_get_true_extent(dtype, &true_lb, &true_extent);
if (MPI_SUCCESS != ret) { line = __LINE__; goto error_hndl; }
ret = ompi_ddt_type_size( dtype, &typelng);
if (MPI_SUCCESS != ret) { line = __LINE__; goto error_hndl; }
/* Determine the number of elements per block and corresponding
block sizes.
The blocks are divided into "early" and "late" ones:
blocks 0 .. (split_rank - 1) are "early" and
blocks (split_rank) .. (size - 1) are "late".
Early blocks are at most 1 element larger than the late ones.
*/
COLL_TUNED_COMPUTE_BLOCKCOUNT( count, size, split_rank,
early_segcount, late_segcount )
max_segcount = early_segcount;
max_real_segsize = true_extent + (max_segcount - 1) * extent;
inbuf[0] = (char*)malloc(max_real_segsize);
if (NULL == inbuf[0]) { ret = -1; line = __LINE__; goto error_hndl; }
if (size > 2) {
inbuf[1] = (char*)malloc(max_real_segsize);
if (NULL == inbuf[1]) { ret = -1; line = __LINE__; goto error_hndl; }
}
/* Handle MPI_IN_PLACE */
if (MPI_IN_PLACE != sbuf) {
ret = ompi_ddt_copy_content_same_ddt(dtype, count, (char*)rbuf, (char*)sbuf);
if (ret < 0) { line = __LINE__; goto error_hndl; }
}
/* Computation loop */
/*
For each of the remote nodes:
- post irecv for block (r-1)
- send block (r)
- in loop for every step k = 2 .. n
- post irecv for block (r + n - k) % n
- wait on block (r + n - k + 1) % n to arrive
- compute on block (r + n - k + 1) % n
- send block (r + n - k + 1) % n
- wait on block (r + 1)
- compute on block (r + 1)
- send block (r + 1) to rank (r + 1)
Note that we must be careful when computing the begining of buffers and
for send operations and computation we must compute the exact block size.
*/
send_to = (rank + 1) % size;
recv_from = (rank + size - 1) % size;
inbi = 0;
/* Initialize first receive from the neighbor on the left */
ret = MCA_PML_CALL(irecv(inbuf[inbi], max_segcount, dtype, recv_from,
MCA_COLL_BASE_TAG_ALLREDUCE, comm, &reqs[inbi]));
if (MPI_SUCCESS != ret) { line = __LINE__; goto error_hndl; }
/* Send first block (my block) to the neighbor on the right */
block_offset = ((rank < split_rank)?
(rank * early_segcount) :
(rank * late_segcount + split_rank));
block_count = ((rank < split_rank)? early_segcount : late_segcount);
tmpsend = ((char*)rbuf) + block_offset * extent;
ret = MCA_PML_CALL(send(tmpsend, block_count, dtype, send_to,
MCA_COLL_BASE_TAG_ALLREDUCE,
MCA_PML_BASE_SEND_STANDARD, comm));
if (MPI_SUCCESS != ret) { line = __LINE__; goto error_hndl; }
for (k = 2; k < size; k++) {
const int prevblock = (rank + size - k + 1) % size;
inbi = inbi ^ 0x1;
/* Post irecv for the current block */
ret = MCA_PML_CALL(irecv(inbuf[inbi], max_segcount, dtype, recv_from,
MCA_COLL_BASE_TAG_ALLREDUCE, comm, &reqs[inbi]));
if (MPI_SUCCESS != ret) { line = __LINE__; goto error_hndl; }
/* Wait on previous block to arrive */
ret = ompi_request_wait(&reqs[inbi ^ 0x1], MPI_STATUS_IGNORE);
if (MPI_SUCCESS != ret) { line = __LINE__; goto error_hndl; }
/* Apply operation on previous block: result goes to rbuf
rbuf[prevblock] = inbuf[inbi ^ 0x1] (op) rbuf[prevblock]
*/
block_offset = ((prevblock < split_rank)?
(prevblock * early_segcount) :
(prevblock * late_segcount + split_rank));
block_count = ((prevblock < split_rank)? early_segcount : late_segcount);
tmprecv = ((char*)rbuf) + block_offset * extent;
ompi_op_reduce(op, inbuf[inbi ^ 0x1], tmprecv, block_count, dtype);
/* send previous block to send_to */
ret = MCA_PML_CALL(send(tmprecv, block_count, dtype, send_to,
MCA_COLL_BASE_TAG_ALLREDUCE,
MCA_PML_BASE_SEND_STANDARD, comm));
if (MPI_SUCCESS != ret) { line = __LINE__; goto error_hndl; }
}
/* Wait on the last block to arrive */
ret = ompi_request_wait(&reqs[inbi], MPI_STATUS_IGNORE);
if (MPI_SUCCESS != ret) { line = __LINE__; goto error_hndl; }
/* Apply operation on the last block (from neighbor (rank + 1)
rbuf[rank+1] = inbuf[inbi] (op) rbuf[rank + 1] */
recv_from = (rank + 1) % size;
block_offset = ((recv_from < split_rank)?
(recv_from * early_segcount) :
(recv_from * late_segcount + split_rank));
block_count = ((recv_from < split_rank)? early_segcount : late_segcount);
tmprecv = ((char*)rbuf) + block_offset * extent;
ompi_op_reduce(op, inbuf[inbi], tmprecv, block_count, dtype);
/* Distribution loop - variation of ring allgather */
send_to = (rank + 1) % size;
recv_from = (rank + size - 1) % size;
for (k = 0; k < size - 1; k++) {
const int recv_data_from = (rank + size - k) % size;
const int send_data_from = (rank + 1 + size - k) % size;
const int send_block_offset =
((send_data_from < split_rank)?
(send_data_from * early_segcount) :
(send_data_from * late_segcount + split_rank));
const int recv_block_offset =
((recv_data_from < split_rank)?
(recv_data_from * early_segcount) :
(recv_data_from * late_segcount + split_rank));
block_count = ((send_data_from < split_rank)?
early_segcount : late_segcount);
tmprecv = (char*)rbuf + recv_block_offset * extent;
tmpsend = (char*)rbuf + send_block_offset * extent;
ret = ompi_coll_tuned_sendrecv(tmpsend, block_count, dtype, send_to,
MCA_COLL_BASE_TAG_ALLREDUCE,
tmprecv, max_segcount, dtype, recv_from,
MCA_COLL_BASE_TAG_ALLREDUCE,
comm, MPI_STATUS_IGNORE, rank);
if (MPI_SUCCESS != ret) { line = __LINE__; goto error_hndl;}
}
if (NULL != inbuf[0]) free(inbuf[0]);
if (NULL != inbuf[1]) free(inbuf[1]);
return MPI_SUCCESS;
error_hndl:
ORTE_OUTPUT((ompi_coll_tuned_stream, "%s:%4d\tRank %d Error occurred %d\n",
__FILE__, line, rank, ret));
if (NULL != inbuf[0]) free(inbuf[0]);
if (NULL != inbuf[1]) free(inbuf[1]);
return ret;
}
/*
* ompi_coll_tuned_allreduce_intra_ring_segmented
*
* Function: Pipelined ring algorithm for allreduce operation
* Accepts: Same as MPI_Allreduce(), segment size
* Returns: MPI_SUCCESS or error code
*
* Description: Implements pipelined ring algorithm for allreduce:
* user supplies suggested segment size for the pipelining of
* reduce operation.
* The segment size determines the number of phases, np, for
* the algorithm execution.
* The message is automatically divided into blocks of
* approximately (count / (np * segcount)) elements.
* At the end of reduction phase, allgather like step is
* executed.
* Algorithm requires (np + 1)*(N - 1) steps.
*
* Limitations: The algorithm DOES NOT preserve order of operations so it
* can be used only for commutative operations.
* In addition, algorithm cannot work if the total size is
* less than size * segment size.
* Example on 3 nodes with 2 phases
* Initial state
* # 0 1 2
* [00a] [10a] [20a]
* [00b] [10b] [20b]
* [01a] [11a] [21a]
* [01b] [11b] [21b]
* [02a] [12a] [22a]
* [02b] [12b] [22b]
*
* COMPUTATION PHASE 0 (a)
* Step 0: rank r sends block ra to rank (r+1) and receives bloc (r-1)a
* from rank (r-1) [with wraparound].
* # 0 1 2
* [00a] [00a+10a] [20a]
* [00b] [10b] [20b]
* [01a] [11a] [11a+21a]
* [01b] [11b] [21b]
* [22a+02a] [12a] [22a]
* [02b] [12b] [22b]
*
* Step 1: rank r sends block (r-1)a to rank (r+1) and receives bloc
* (r-2)a from rank (r-1) [with wraparound].
* # 0 1 2
* [00a] [00a+10a] [00a+10a+20a]
* [00b] [10b] [20b]
* [11a+21a+01a] [11a] [11a+21a]
* [01b] [11b] [21b]
* [22a+02a] [22a+02a+12a] [22a]
* [02b] [12b] [22b]
*
* COMPUTATION PHASE 1 (b)
* Step 0: rank r sends block rb to rank (r+1) and receives bloc (r-1)b
* from rank (r-1) [with wraparound].
* # 0 1 2
* [00a] [00a+10a] [20a]
* [00b] [00b+10b] [20b]
* [01a] [11a] [11a+21a]
* [01b] [11b] [11b+21b]
* [22a+02a] [12a] [22a]
* [22b+02b] [12b] [22b]
*
* Step 1: rank r sends block (r-1)b to rank (r+1) and receives bloc
* (r-2)b from rank (r-1) [with wraparound].
* # 0 1 2
* [00a] [00a+10a] [00a+10a+20a]
* [00b] [10b] [0bb+10b+20b]
* [11a+21a+01a] [11a] [11a+21a]
* [11b+21b+01b] [11b] [21b]
* [22a+02a] [22a+02a+12a] [22a]
* [02b] [22b+01b+12b] [22b]
*
*
* DISTRIBUTION PHASE: ring ALLGATHER with ranks shifted by 1 (same as
* in regular ring algorithm.
*
*/
int
ompi_coll_tuned_allreduce_intra_ring_segmented(void *sbuf, void *rbuf, int count,
struct ompi_datatype_t *dtype,
struct ompi_op_t *op,
struct ompi_communicator_t *comm,
struct mca_coll_base_module_1_1_0_t *module,
uint32_t segsize)
{
int ret, line;
int rank, size, k, recv_from, send_to;
int early_blockcount, late_blockcount, split_rank;
int segcount, max_segcount;
int num_phases, phase;
int block_count, inbi;
size_t typelng;
char *tmpsend = NULL, *tmprecv = NULL;
char *inbuf[2] = {NULL, NULL};
ptrdiff_t true_lb, true_extent, lb, extent;
ptrdiff_t block_offset, max_real_segsize;
ompi_request_t *reqs[2] = {NULL, NULL};
size = ompi_comm_size(comm);
rank = ompi_comm_rank(comm);
ORTE_OUTPUT((ompi_coll_tuned_stream,
"coll:tuned:allreduce_intra_ring_segmented rank %d, count %d", rank, count));
/* Special case for size == 1 */
if (1 == size) {
if (MPI_IN_PLACE != sbuf) {
ret = ompi_ddt_copy_content_same_ddt(dtype, count, (char*)rbuf, (char*)sbuf);
if (ret < 0) { line = __LINE__; goto error_hndl; }
}
return MPI_SUCCESS;
}
/* Determine segment count based on the suggested segment size */
ret = ompi_ddt_get_extent(dtype, &lb, &extent);
if (MPI_SUCCESS != ret) { line = __LINE__; goto error_hndl; }
ret = ompi_ddt_get_true_extent(dtype, &true_lb, &true_extent);
if (MPI_SUCCESS != ret) { line = __LINE__; goto error_hndl; }
ret = ompi_ddt_type_size( dtype, &typelng);
if (MPI_SUCCESS != ret) { line = __LINE__; goto error_hndl; }
segcount = count;
COLL_TUNED_COMPUTED_SEGCOUNT(segsize, typelng, segcount)
/* Special case for count less than size * segcount - use regular ring */
if (count < size * segcount) {
ORTE_OUTPUT((ompi_coll_tuned_stream, "coll:tuned:allreduce_ring_segmented rank %d/%d, count %d, switching to regular ring", rank, size, count));
return (ompi_coll_tuned_allreduce_intra_ring(sbuf, rbuf, count, dtype, op,
comm, module));
}
/* Determine the number of phases of the algorithm */
num_phases = count / (size * segcount);
if ((count % (size * segcount) >= size) &&
(count % (size * segcount) > ((size * segcount) / 2))) {
num_phases++;
}
/* Determine the number of elements per block and corresponding
block sizes.
The blocks are divided into "early" and "late" ones:
blocks 0 .. (split_rank - 1) are "early" and
blocks (split_rank) .. (size - 1) are "late".
Early blocks are at most 1 element larger than the late ones.
Note, these blocks will be split into num_phases segments,
out of the largest one will have max_segcount elements.
*/
COLL_TUNED_COMPUTE_BLOCKCOUNT( count, size, split_rank,
early_blockcount, late_blockcount )
COLL_TUNED_COMPUTE_BLOCKCOUNT( early_blockcount, num_phases, inbi,
max_segcount, k)
max_real_segsize = true_extent + (max_segcount - 1) * extent;
/* Allocate and initialize temporary buffers */
inbuf[0] = (char*)malloc(max_real_segsize);
if (NULL == inbuf[0]) { ret = -1; line = __LINE__; goto error_hndl; }
if (size > 2) {
inbuf[1] = (char*)malloc(max_real_segsize);
if (NULL == inbuf[1]) { ret = -1; line = __LINE__; goto error_hndl; }
}
/* Handle MPI_IN_PLACE */
if (MPI_IN_PLACE != sbuf) {
ret = ompi_ddt_copy_content_same_ddt(dtype, count, (char*)rbuf, (char*)sbuf);
if (ret < 0) { line = __LINE__; goto error_hndl; }
}
/* Computation loop: for each phase, repeat ring allreduce computation loop */
for (phase = 0; phase < num_phases; phase ++) {
ptrdiff_t phase_offset;
int early_phase_segcount, late_phase_segcount, split_phase, phase_count;
/*
For each of the remote nodes:
- post irecv for block (r-1)
- send block (r)
To do this, first compute block offset and count, and use block offset
to compute phase offset.
- in loop for every step k = 2 .. n
- post irecv for block (r + n - k) % n
- wait on block (r + n - k + 1) % n to arrive
- compute on block (r + n - k + 1) % n
- send block (r + n - k + 1) % n
- wait on block (r + 1)
- compute on block (r + 1)
- send block (r + 1) to rank (r + 1)
Note that we must be careful when computing the begining of buffers and
for send operations and computation we must compute the exact block size.
*/
send_to = (rank + 1) % size;
recv_from = (rank + size - 1) % size;
inbi = 0;
/* Initialize first receive from the neighbor on the left */
ret = MCA_PML_CALL(irecv(inbuf[inbi], max_segcount, dtype, recv_from,
MCA_COLL_BASE_TAG_ALLREDUCE, comm, &reqs[inbi]));
if (MPI_SUCCESS != ret) { line = __LINE__; goto error_hndl; }
/* Send first block (my block) to the neighbor on the right:
- compute my block and phase offset
- send data */
block_offset = ((rank < split_rank)?
(rank * early_blockcount) :
(rank * late_blockcount + split_rank));
block_count = ((rank < split_rank)? early_blockcount : late_blockcount);
COLL_TUNED_COMPUTE_BLOCKCOUNT(block_count, num_phases, split_phase,
early_phase_segcount, late_phase_segcount)
phase_count = ((phase < split_phase)?
(early_phase_segcount) : (late_phase_segcount));
phase_offset = ((phase < split_phase)?
(phase * early_phase_segcount) :
(phase * late_phase_segcount + split_phase));
tmpsend = ((char*)rbuf) + (block_offset + phase_offset) * extent;
ret = MCA_PML_CALL(send(tmpsend, phase_count, dtype, send_to,
MCA_COLL_BASE_TAG_ALLREDUCE,
MCA_PML_BASE_SEND_STANDARD, comm));
if (MPI_SUCCESS != ret) { line = __LINE__; goto error_hndl; }
for (k = 2; k < size; k++) {
const int prevblock = (rank + size - k + 1) % size;
inbi = inbi ^ 0x1;
/* Post irecv for the current block */
ret = MCA_PML_CALL(irecv(inbuf[inbi], max_segcount, dtype, recv_from,
MCA_COLL_BASE_TAG_ALLREDUCE, comm,
&reqs[inbi]));
if (MPI_SUCCESS != ret) { line = __LINE__; goto error_hndl; }
/* Wait on previous block to arrive */
ret = ompi_request_wait(&reqs[inbi ^ 0x1], MPI_STATUS_IGNORE);
if (MPI_SUCCESS != ret) { line = __LINE__; goto error_hndl; }
/* Apply operation on previous block: result goes to rbuf
rbuf[prevblock] = inbuf[inbi ^ 0x1] (op) rbuf[prevblock]
*/
block_offset = ((prevblock < split_rank)?
(prevblock * early_blockcount) :
(prevblock * late_blockcount + split_rank));
block_count = ((prevblock < split_rank)?
early_blockcount : late_blockcount);
COLL_TUNED_COMPUTE_BLOCKCOUNT(block_count, num_phases, split_phase,
early_phase_segcount, late_phase_segcount)
phase_count = ((phase < split_phase)?
(early_phase_segcount) : (late_phase_segcount));
phase_offset = ((phase < split_phase)?
(phase * early_phase_segcount) :
(phase * late_phase_segcount + split_phase));
tmprecv = ((char*)rbuf) + (block_offset + phase_offset) * extent;
ompi_op_reduce(op, inbuf[inbi ^ 0x1], tmprecv, phase_count, dtype);
/* send previous block to send_to */
ret = MCA_PML_CALL(send(tmprecv, phase_count, dtype, send_to,
MCA_COLL_BASE_TAG_ALLREDUCE,
MCA_PML_BASE_SEND_STANDARD, comm));
if (MPI_SUCCESS != ret) { line = __LINE__; goto error_hndl; }
}
/* Wait on the last block to arrive */
ret = ompi_request_wait(&reqs[inbi], MPI_STATUS_IGNORE);
if (MPI_SUCCESS != ret) { line = __LINE__; goto error_hndl; }
/* Apply operation on the last block (from neighbor (rank + 1)
rbuf[rank+1] = inbuf[inbi] (op) rbuf[rank + 1] */
recv_from = (rank + 1) % size;
block_offset = ((recv_from < split_rank)?
(recv_from * early_blockcount) :
(recv_from * late_blockcount + split_rank));
block_count = ((recv_from < split_rank)?
early_blockcount : late_blockcount);
COLL_TUNED_COMPUTE_BLOCKCOUNT(block_count, num_phases, split_phase,
early_phase_segcount, late_phase_segcount)
phase_count = ((phase < split_phase)?
(early_phase_segcount) : (late_phase_segcount));
phase_offset = ((phase < split_phase)?
(phase * early_phase_segcount) :
(phase * late_phase_segcount + split_phase));
tmprecv = ((char*)rbuf) + (block_offset + phase_offset) * extent;
ompi_op_reduce(op, inbuf[inbi], tmprecv, phase_count, dtype);
}
/* Distribution loop - variation of ring allgather */
send_to = (rank + 1) % size;
recv_from = (rank + size - 1) % size;
for (k = 0; k < size - 1; k++) {
const int recv_data_from = (rank + size - k) % size;
const int send_data_from = (rank + 1 + size - k) % size;
const int send_block_offset =
((send_data_from < split_rank)?
(send_data_from * early_blockcount) :
(send_data_from * late_blockcount + split_rank));
const int recv_block_offset =
((recv_data_from < split_rank)?
(recv_data_from * early_blockcount) :
(recv_data_from * late_blockcount + split_rank));
block_count = ((send_data_from < split_rank)?
early_blockcount : late_blockcount);
tmprecv = (char*)rbuf + recv_block_offset * extent;
tmpsend = (char*)rbuf + send_block_offset * extent;
ret = ompi_coll_tuned_sendrecv(tmpsend, block_count, dtype, send_to,
MCA_COLL_BASE_TAG_ALLREDUCE,
tmprecv, early_blockcount, dtype, recv_from,
MCA_COLL_BASE_TAG_ALLREDUCE,
comm, MPI_STATUS_IGNORE, rank);
if (MPI_SUCCESS != ret) { line = __LINE__; goto error_hndl;}
}
if (NULL != inbuf[0]) free(inbuf[0]);
if (NULL != inbuf[1]) free(inbuf[1]);
return MPI_SUCCESS;
error_hndl:
ORTE_OUTPUT((ompi_coll_tuned_stream, "%s:%4d\tRank %d Error occurred %d\n",
__FILE__, line, rank, ret));
if (NULL != inbuf[0]) free(inbuf[0]);
if (NULL != inbuf[1]) free(inbuf[1]);
return ret;
}
/*
* Linear functions are copied from the BASIC coll module
* they do not segment the message and are simple implementations
* but for some small number of nodes and/or small data sizes they
* are just as fast as tuned/tree based segmenting operations
* and as such may be selected by the decision functions
* These are copied into this module due to the way we select modules
* in V1. i.e. in V2 we will handle this differently and so will not
* have to duplicate code.
* GEF Oct05 after asking Jeff.
*/
/* copied function (with appropriate renaming) starts here */
/*
* allreduce_intra
*
* Function: - allreduce using other MPI collectives
* Accepts: - same as MPI_Allreduce()
* Returns: - MPI_SUCCESS or error code
*/
int
ompi_coll_tuned_allreduce_intra_basic_linear(void *sbuf, void *rbuf, int count,
struct ompi_datatype_t *dtype,
struct ompi_op_t *op,
struct ompi_communicator_t *comm,
struct mca_coll_base_module_1_1_0_t *module)
{
int err;
int rank;
rank = ompi_comm_rank(comm);
ORTE_OUTPUT((ompi_coll_tuned_stream,"coll:tuned:allreduce_intra_basic_linear rank %d", rank));
/* Reduce to 0 and broadcast. */
if (MPI_IN_PLACE == sbuf) {
if (0 == ompi_comm_rank(comm)) {
err = ompi_coll_tuned_reduce_intra_basic_linear (MPI_IN_PLACE, rbuf, count, dtype,
op, 0, comm, module);
} else {
err = ompi_coll_tuned_reduce_intra_basic_linear(rbuf, NULL, count, dtype,
op, 0, comm, module);
}
} else {
err = ompi_coll_tuned_reduce_intra_basic_linear(sbuf, rbuf, count, dtype,
op, 0, comm, module);
}
if (MPI_SUCCESS != err) {
return err;
}
return ompi_coll_tuned_bcast_intra_basic_linear(rbuf, count, dtype, 0, comm, module);
}
/* copied function (with appropriate renaming) ends here */
/* The following are used by dynamic and forced rules */
/* publish details of each algorithm and if its forced/fixed/locked in */
/* as you add methods/algorithms you must update this and the query/map routines */
/* this routine is called by the component only */
/* this makes sure that the mca parameters are set to their initial values and perms */
/* module does not call this they call the forced_getvalues routine instead */
int ompi_coll_tuned_allreduce_intra_check_forced_init (coll_tuned_force_algorithm_mca_param_indices_t *mca_param_indices)
{
int max_alg = 5, requested_alg;
ompi_coll_tuned_forced_max_algorithms[ALLREDUCE] = max_alg;
mca_base_param_reg_int (&mca_coll_tuned_component.super.collm_version,
"allreduce_algorithm_count",
"Number of allreduce algorithms available",
false, true, max_alg, NULL);
mca_param_indices->algorithm_param_index
= mca_base_param_reg_int( &mca_coll_tuned_component.super.collm_version,
"allreduce_algorithm",
"Which allreduce algorithm is used. Can be locked down to any of: 0 ignore, 1 basic linear, 2 nonoverlapping (tuned reduce + tuned bcast), 3 recursive doubling, 4 ring, 5 segmented ring",
false, false, 0, NULL);
mca_base_param_lookup_int( mca_param_indices->algorithm_param_index, &(requested_alg));
if( requested_alg > max_alg ) {
if( 0 == ompi_comm_rank( MPI_COMM_WORLD ) ) {
orte_output( 0, "Allreduce algorithm #%d is not available (range [0..%d]). Switching back to ignore(0)\n",
requested_alg, max_alg );
}
mca_base_param_set_int( mca_param_indices->algorithm_param_index, 0);
}
mca_param_indices->segsize_param_index
= mca_base_param_reg_int( &mca_coll_tuned_component.super.collm_version,
"allreduce_algorithm_segmentsize",
"Segment size in bytes used by default for allreduce algorithms. Only has meaning if algorithm is forced and supports segmenting. 0 bytes means no segmentation.",
false, false, 0, NULL);
mca_param_indices->tree_fanout_param_index
= mca_base_param_reg_int( &mca_coll_tuned_component.super.collm_version,
"allreduce_algorithm_tree_fanout",
"Fanout for n-tree used for allreduce algorithms. Only has meaning if algorithm is forced and supports n-tree topo based operation.",
false, false, ompi_coll_tuned_init_tree_fanout, /* get system wide default */
NULL);
mca_param_indices->chain_fanout_param_index
= mca_base_param_reg_int( &mca_coll_tuned_component.super.collm_version,
"allreduce_algorithm_chain_fanout",
"Fanout for chains used for allreduce algorithms. Only has meaning if algorithm is forced and supports chain topo based operation.",
false, false,
ompi_coll_tuned_init_chain_fanout, /* get system wide default */
NULL);
return (MPI_SUCCESS);
}
int ompi_coll_tuned_allreduce_intra_do_forced(void *sbuf, void *rbuf, int count,
struct ompi_datatype_t *dtype,
struct ompi_op_t *op,
struct ompi_communicator_t *comm,
struct mca_coll_base_module_1_1_0_t *module)
{
mca_coll_tuned_module_t *tuned_module = (mca_coll_tuned_module_t*) module;
mca_coll_tuned_comm_t *data = tuned_module->tuned_data;
ORTE_OUTPUT((ompi_coll_tuned_stream,"coll:tuned:allreduce_intra_do_forced selected algorithm %d, segment size %d",
data->user_forced[ALLREDUCE].algorithm,
data->user_forced[ALLREDUCE].segsize));
switch (data->user_forced[ALLREDUCE].algorithm) {
case (0): return ompi_coll_tuned_allreduce_intra_dec_fixed (sbuf, rbuf, count, dtype, op, comm, module);
case (1): return ompi_coll_tuned_allreduce_intra_basic_linear (sbuf, rbuf, count, dtype, op, comm, module);
case (2): return ompi_coll_tuned_allreduce_intra_nonoverlapping (sbuf, rbuf, count, dtype, op, comm, module);
case (3): return ompi_coll_tuned_allreduce_intra_recursivedoubling (sbuf, rbuf, count, dtype, op, comm, module);
case (4): return ompi_coll_tuned_allreduce_intra_ring (sbuf, rbuf, count, dtype, op, comm, module);
case (5): return ompi_coll_tuned_allreduce_intra_ring_segmented (sbuf, rbuf, count, dtype, op, comm, module, data->user_forced[ALLREDUCE].segsize);
default:
ORTE_OUTPUT((ompi_coll_tuned_stream,"coll:tuned:allreduce_intra_do_forced attempt to select algorithm %d when only 0-%d is valid?",
data->user_forced[ALLREDUCE].algorithm,
ompi_coll_tuned_forced_max_algorithms[ALLREDUCE]));
return (MPI_ERR_ARG);
} /* switch */
}
int ompi_coll_tuned_allreduce_intra_do_this(void *sbuf, void *rbuf, int count,
struct ompi_datatype_t *dtype,
struct ompi_op_t *op,
struct ompi_communicator_t *comm,
struct mca_coll_base_module_1_1_0_t *module,
int algorithm, int faninout, int segsize)
{
ORTE_OUTPUT((ompi_coll_tuned_stream,"coll:tuned:allreduce_intra_do_this algorithm %d topo fan in/out %d segsize %d",
algorithm, faninout, segsize));
switch (algorithm) {
case (0): return ompi_coll_tuned_allreduce_intra_dec_fixed (sbuf, rbuf, count, dtype, op, comm, module);
case (1): return ompi_coll_tuned_allreduce_intra_basic_linear (sbuf, rbuf, count, dtype, op, comm, module);
case (2): return ompi_coll_tuned_allreduce_intra_nonoverlapping (sbuf, rbuf, count, dtype, op, comm, module);
case (3): return ompi_coll_tuned_allreduce_intra_recursivedoubling (sbuf, rbuf, count, dtype, op, comm, module);
case (4): return ompi_coll_tuned_allreduce_intra_ring (sbuf, rbuf, count, dtype, op, comm, module);
case (5): return ompi_coll_tuned_allreduce_intra_ring_segmented (sbuf, rbuf, count, dtype, op, comm, module, segsize);
default:
ORTE_OUTPUT((ompi_coll_tuned_stream,"coll:tuned:allreduce_intra_do_this attempt to select algorithm %d when only 0-%d is valid?",
algorithm, ompi_coll_tuned_forced_max_algorithms[ALLREDUCE]));
return (MPI_ERR_ARG);
} /* switch */
}
Показать git blame Копировать постоянную ссылку