>From 3dd2a470c37c0eb3952dab12b63f5451f5d18aa8 Mon Sep 17 00:00:00 2001
From: Alan D. Brunelle <alan.brunelle@xxxxxx>
Date: Wed, 11 Feb 2009 13:58:14 -0500
Subject: [PATCH] Increased limits fix for blkparse
As with blktrace & btt, added in code to blkparse to handle increasing
the file limits when open errors encountered.
I'm _not_ pushing this out as Jens isn't here, and I don't feel
comfortable playing with the blkparse stuff in his tree. [Anyways, it
seems best to extract this common code and put it somewhere for
blktrace, blkparse & btt to all reference.]
I'm posting this in case anyone else is running into problems with
handling large numbers of cpus/devices. [I'm working on 32 CPUs and 88
devices right now.]
Signed-off-by: Alan D. Brunelle <alan.brunelle@xxxxxx>
---
blkparse.c | 77 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++----
1 files changed, 72 insertions(+), 5 deletions(-)
diff --git a/blkparse.c b/blkparse.c
index ef55697..922eb19 100644
--- a/blkparse.c
+++ b/blkparse.c
@@ -31,6 +31,8 @@
#include <signal.h>
#include <locale.h>
#include <libgen.h>
+#include <sys/time.h>
+#include <sys/resource.h>
#include "blktrace.h"
#include "rbtree.h"
@@ -306,6 +308,71 @@ static int have_drv_data = 0;
#define CPU_IDX(cpu) ((cpu) / CPUS_PER_LONG)
#define CPU_BIT(cpu) ((cpu) & (CPUS_PER_LONG - 1))
+/*
+ * Due to the N(devs) parts of a lot of the output features provided
+ * by btt, it will fail opens on large(ish) systems. Here we try to
+ * keep bumping our open file limits, and if those fail, we return NULL.
+ *
+ * Root users will probably be OK with this, others...
+ */
+static int increase_limit(int resource, rlim_t increase)
+{
+ struct rlimit rlim;
+ int save_errno = errno;
+
+ if (!getrlimit(resource, &rlim)) {
+ rlim.rlim_cur += increase;
+ if (rlim.rlim_cur >= rlim.rlim_max)
+ rlim.rlim_max = rlim.rlim_cur + increase;
+
+ if (!setrlimit(resource, &rlim))
+ return 1;
+ }
+
+ errno = save_errno;
+ return 0;
+}
+
+static int handle_open_failure(void)
+{
+ if (errno == ENFILE || errno == EMFILE)
+ return increase_limit(RLIMIT_NOFILE, 16);
+ return 0;
+}
+
+FILE *my_fopen(const char *path, const char *mode)
+{
+ FILE *fp;
+
+ do {
+ fp = fopen(path, mode);
+ } while (fp == NULL && handle_open_failure());
+
+ return fp;
+}
+
+FILE *my_fdopen(int fd, const char *mode)
+{
+ FILE *fp;
+
+ do {
+ fp = fdopen(fd, mode);
+ } while (fp == NULL && handle_open_failure());
+
+ return fp;
+}
+
+int my_open(const char *path, int flags)
+{
+ int fd;
+
+ do {
+ fd = open(path, flags);
+ } while (fd < 0 && handle_open_failure());
+
+ return fd;
+}
+
static void output_binary(void *buf, int len)
{
if (dump_binary) {
@@ -2434,7 +2501,7 @@ static int setup_file(struct per_dev_info *pdi, int cpu)
if (!st.st_size)
return 1;
- pci->fd = open(pci->fname, O_RDONLY);
+ pci->fd = my_open(pci->fname, O_RDONLY);
if (pci->fd < 0) {
perror(pci->fname);
return 0;
@@ -2569,7 +2636,7 @@ static int do_fifo(void)
if (!strcmp(pipename, "-"))
fd = dup(STDIN_FILENO);
else
- fd = open(pipename, O_RDONLY);
+ fd = my_open(pipename, O_RDONLY);
if (fd == -1) {
perror("dup stdin");
@@ -2817,13 +2884,13 @@ int main(int argc, char *argv[])
if (text_output) {
if (!output_name) {
- ofp = fdopen(STDOUT_FILENO, "w");
+ ofp = my_fdopen(STDOUT_FILENO, "w");
mode = _IOLBF;
} else {
char ofname[128];
snprintf(ofname, sizeof(ofname) - 1, "%s", output_name);
- ofp = fopen(ofname, "w");
+ ofp = my_fopen(ofname, "w");
mode = _IOFBF;
}
@@ -2840,7 +2907,7 @@ int main(int argc, char *argv[])
}
if (dump_binary) {
- dump_fp = fopen(dump_binary, "w");
+ dump_fp = my_fopen(dump_binary, "w");
if (!dump_fp) {
perror(dump_binary);
dump_binary = NULL;
--
1.5.6.3
