Messages in this thread |  | | Date | Tue, 27 Nov 2001 20:54:24 +0300 | From | Peter Zaitsev <> | Subject | Re[2]: MMAP issues |
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Hello Andrew,
Tuesday, November 27, 2001, 8:44:40 PM, you wrote:
OK. Of course. It's just a few lines length: Just mention to create any "test.dat" file in the current directory;
#include <stdio.h> #include <unistd.h> #include <sys/mman.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <errno.h>
int main() { int i=0; void* p; int t; int fd; t=time(NULL); while(1) { fd=open("test.dat",O_RDWR); if (fd<0) { puts("Unable to open file !"); return; } p=mmap(NULL,4096, PROT_READ | PROT_WRITE , MAP_PRIVATE ,fd ,0); if ((int)p==-1) { printf("Failed %d\n",errno); return; } i++; if (i%10000==0) { printf(" %d Time: %d\n",i,time(NULL)-t); t=time(NULL); } } }
AM> Peter Zaitsev wrote: >> >> Hello , >> >> I'm trying to write a program which uses mmap agressively to mmap >> files (really it's used as fail safe memory allocator to store data >> if application failed) >>
AM> It would really help if you could make your test application available to AM> the kernel developers.
AM> Thanks.
Additionally the interesting thing is - if I change MMAP params to: p=mmap(NULL,4096, PROT_READ | PROT_WRITE , MAP_PRIVATE | MAP_ANON ,-1 ,0);
(The only change is mapping done ammoniums instead of mmaping a file - this increases speed really much and it does not decrease)
-- Best regards, Peter mailto:pz@spylog.ru
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