diff options
Diffstat (limited to 'open_issues/performance/io_system')
| -rw-r--r-- | open_issues/performance/io_system/binutils_ld_64ksec.mdwn | 6 | ||||
| -rw-r--r-- | open_issues/performance/io_system/test-lseek.c | 17 | ||||
| -rw-r--r-- | open_issues/performance/io_system/test-mach.c | 19 |
3 files changed, 42 insertions, 0 deletions
diff --git a/open_issues/performance/io_system/binutils_ld_64ksec.mdwn b/open_issues/performance/io_system/binutils_ld_64ksec.mdwn index 359d5fee..d0b8ea7f 100644 --- a/open_issues/performance/io_system/binutils_ld_64ksec.mdwn +++ b/open_issues/performance/io_system/binutils_ld_64ksec.mdwn @@ -27,6 +27,10 @@ extracted from cdf7c161ebd4a934c9e705d33f5247fd52975612 sources, 2010-10-24. On the idle grubber, this one repeatedly takes a few minutes wall time to complete successfully, contrary to a few seconds on a GNU/Linux system. +> On order of slowness may in fact be due to a Xen-specific issue, see +> [[xen_lseek]]. (But there are probably still one or two orders left, even +> without Xen.) + While processing the object files, there is heavy interaction with the relevant [[hurd/translator/ext2fs]] process. Running [[hurd/debugging/rpctrace]] on the testee shows that (primarily) an ever-repeating series of `io_seek` and @@ -47,4 +51,6 @@ IRC, freenode, #hurd, 2011-09-01: <youpi> (fgetpos actually, but that's the same) <youpi> and it is indeed about 10 times slower under Xen for some reason +Also see testcase [[test-lseek.c]] and [[test-mach.c]] + [[!tag open_issue_xen]] diff --git a/open_issues/performance/io_system/test-lseek.c b/open_issues/performance/io_system/test-lseek.c new file mode 100644 index 00000000..667dce66 --- /dev/null +++ b/open_issues/performance/io_system/test-lseek.c @@ -0,0 +1,17 @@ +#include <stdio.h> +#include <math.h> +#include <fcntl.h> +#include <unistd.h> +#include <sys/time.h> +#define N 100000 +int main(void) { + int fd = open("test.c", O_RDONLY); + struct timeval tv1, tv2; + int i; + gettimeofday(&tv1, NULL); + for (i = 0; i < N; i++) + lseek(fd, 0, SEEK_CUR); + gettimeofday(&tv2, NULL); + printf("%fµs\n", (float)((tv2.tv_sec-tv1.tv_sec) * 1000000 + tv2.tv_usec - tv1.tv_usec)/N); + return 0; +} diff --git a/open_issues/performance/io_system/test-mach.c b/open_issues/performance/io_system/test-mach.c new file mode 100644 index 00000000..90337346 --- /dev/null +++ b/open_issues/performance/io_system/test-mach.c @@ -0,0 +1,19 @@ +#define _GNU_SOURCE +#include <stdio.h> +#include <fcntl.h> +#include <mach/mach.h> +#define N 1000000 +int main(void) { + struct timeval tv1, tv2; + int i; + task_t task; + task = mach_task_self(); + mach_port_urefs_t refs; + gettimeofday(&tv1, NULL); + for (i = 0; i < N; i++) { + mach_port_get_refs(task, task, MACH_PORT_RIGHT_RECEIVE, &refs); + } + gettimeofday(&tv2, NULL); + printf("%fµs\n", (float)((tv2.tv_sec-tv1.tv_sec) * 1000000 + tv2.tv_usec - tv1.tv_usec)/N); + return 0; +} |