Files
ubports_kernel_google_msm/include/linux
Jens Axboe f6762b7ad8 [PATCH] pipe: enable atomic copying of pipe data to/from user space
The pipe ->map() method uses kmap() to virtually map the pages, which
is both slow and has known scalability issues on SMP. This patch enables
atomic copying of pipe pages, by pre-faulting data and using kmap_atomic()
instead.

lmbench bw_pipe and lat_pipe measurements agree this is a Good Thing. Here
are results from that on a UP machine with highmem (1.5GiB of RAM), running
first a UP kernel, SMP kernel, and SMP kernel patched.

Vanilla-UP:
Pipe bandwidth: 1622.28 MB/sec
Pipe bandwidth: 1610.59 MB/sec
Pipe bandwidth: 1608.30 MB/sec
Pipe latency: 7.3275 microseconds
Pipe latency: 7.2995 microseconds
Pipe latency: 7.3097 microseconds

Vanilla-SMP:
Pipe bandwidth: 1382.19 MB/sec
Pipe bandwidth: 1317.27 MB/sec
Pipe bandwidth: 1355.61 MB/sec
Pipe latency: 9.6402 microseconds
Pipe latency: 9.6696 microseconds
Pipe latency: 9.6153 microseconds

Patched-SMP:
Pipe bandwidth: 1578.70 MB/sec
Pipe bandwidth: 1579.95 MB/sec
Pipe bandwidth: 1578.63 MB/sec
Pipe latency: 9.1654 microseconds
Pipe latency: 9.2266 microseconds
Pipe latency: 9.1527 microseconds

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-05-01 20:02:05 +02:00
..
2006-01-08 20:14:02 -08:00
2006-03-21 08:52:18 -08:00
2006-02-22 09:32:46 +00:00
2006-03-31 12:18:48 -08:00
2006-01-13 16:29:56 -08:00
2005-11-13 18:14:17 -08:00
2006-03-20 14:08:55 -05:00
2006-01-13 09:12:21 -08:00
2005-10-04 13:22:01 -07:00
2005-06-23 09:45:26 -07:00
2005-09-10 10:06:21 -07:00
2006-03-24 07:33:20 -08:00
2006-03-28 09:16:05 -08:00
2006-03-23 07:38:09 -08:00
2005-09-10 10:16:27 -07:00
2006-03-27 08:44:59 -08:00
2006-01-08 20:14:02 -08:00
2005-05-15 18:31:07 -04:00
2006-03-27 08:44:59 -08:00
2006-01-08 20:13:49 -08:00
2005-05-19 22:43:37 -07:00
2005-11-05 21:00:02 -05:00
2006-03-31 12:18:54 -08:00
2006-01-18 19:20:29 -08:00
2005-07-12 12:08:43 -07:00
2006-04-02 00:08:05 -05:00
2005-06-21 18:46:18 -07:00
2005-11-10 02:26:41 +01:00
2006-04-11 06:18:35 -07:00
2006-01-14 18:27:09 -08:00
2005-07-12 12:08:43 -07:00
2006-03-26 08:56:56 -08:00
2006-03-27 08:44:51 -08:00
2005-06-15 12:38:14 +01:00
2005-11-08 17:14:08 +01:00
2005-05-05 14:25:59 -07:00
2005-11-08 09:40:47 -08:00
2005-07-05 15:03:46 -07:00
2005-08-29 16:01:32 -07:00
2005-09-19 15:41:28 -07:00
2006-03-20 17:09:11 -08:00
2005-08-29 16:01:32 -07:00
2006-03-20 22:41:23 -08:00
2006-01-06 13:24:54 -08:00
2006-04-02 00:10:28 -05:00
2006-02-01 08:53:13 -08:00
2006-02-08 01:03:52 -05:00
2005-06-21 18:46:32 -07:00
2006-01-06 13:24:29 -08:00
2006-03-26 08:56:56 -08:00
2006-03-20 22:21:10 -08:00
2005-11-07 14:18:56 +01:00
2005-09-17 11:50:02 -07:00
2005-10-08 15:00:57 -07:00
2006-04-27 13:08:56 -07:00
2006-03-23 07:38:12 -08:00
2005-10-30 17:37:17 -08:00
2006-03-23 07:38:12 -08:00
2006-03-27 08:44:52 -08:00
2005-10-28 08:16:47 -07:00
2005-09-14 08:46:21 -04:00
2006-03-22 07:53:57 -08:00
2006-03-27 08:44:48 -08:00
2006-03-23 07:38:13 -08:00
2006-03-23 07:38:14 -08:00
2006-03-23 07:38:14 -08:00
2005-06-24 00:06:28 -07:00
2006-03-20 13:44:40 -05:00
2006-03-20 13:44:27 -05:00
2006-04-11 06:18:39 -07:00
2006-04-19 09:13:53 -07:00
2006-03-08 14:14:01 -08:00
2006-01-15 02:12:54 +01:00
2006-03-27 08:44:48 -08:00
2006-03-25 08:22:51 -08:00
2006-03-25 08:22:53 -08:00
2005-11-07 07:53:46 -08:00
2006-03-27 08:44:51 -08:00
2005-10-30 11:14:39 +11:00
2006-01-08 20:14:02 -08:00
2005-11-07 07:53:41 -08:00
2006-03-23 07:38:12 -08:00
2005-10-30 17:37:32 -08:00
2006-04-02 00:08:05 -05:00
2005-11-07 07:53:37 -08:00
2006-01-14 18:27:13 -08:00
2006-03-20 22:41:23 -08:00
2006-03-28 09:16:05 -08:00
2005-09-10 10:06:21 -07:00
2005-09-05 00:05:45 -07:00
2005-10-30 17:37:32 -08:00
2005-09-18 00:18:32 -07:00
2006-03-26 08:57:03 -08:00
2006-03-31 12:18:56 -08:00
2006-01-12 14:06:38 -08:00
2006-01-10 08:01:59 -08:00
2006-03-23 07:38:11 -08:00
2006-03-26 08:57:00 -08:00
2006-03-23 07:38:14 -08:00
2005-07-12 11:52:57 -07:00
2006-03-28 09:16:05 -08:00
2005-10-29 21:40:35 -07:00
2005-11-07 07:53:41 -08:00
2005-07-12 12:08:43 -07:00
2006-03-23 07:12:57 -05:00
2006-01-10 08:01:57 -08:00