linux-ext4 - [Bug 200693] fsync() in the latest kernel (4.15.x ) Broken ????

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <bug-200693-13602-3E6uWjhnxO@https.bugzilla.kernel.org/>
Date:   Tue, 31 Jul 2018 13:52:17 +0000
From:   bugzilla-daemon@...zilla.kernel.org
To:     linux-ext4@...nel.org
Subject: [Bug 200693] fsync() in the latest kernel (4.15.x ) Broken ????

https://bugzilla.kernel.org/show_bug.cgi?id=200693

--- Comment #1 from caron.wills@...il.com ---
4.15.0-29-generic - # time ./fsync
real 1m38.299s <-----
user 0m0.013s
sys 0m0.893s <-----


Source stolen from else where. ;-)

#include <stdio.h>
#include <fcntl.h>
#include <time.h>
#include <unistd.h>


void withSync() {
int f = open( "/tmp/t8" , O_RDWR | O_CREAT );
lseek (f, 0, SEEK_SET );
int records = 10*1000;
clock_t ustart = clock();
for(int i = 0; i < records; i++) {
write(f, "012345678901234567890123456789" , 30);
fsync(f);
}
clock_t uend = clock();
close (f);
printf(" sync() seconds:%lf writes per second:%lf\n",
((double)(uend-ustart))/(CLOCKS_PER_SEC),
((double)records)/((double)(uend-ustart))/(CLOCKS_PER_SEC));
}


void withoutSync() {
int f = open( "/tmp/t10" , O_RDWR | O_CREAT );
lseek (f, 0, SEEK_SET );
int records = 10*1000;
clock_t ustart = clock();
for(int i = 0; i < records; i++) {
write(f, "012345678901234567890123456789" , 30 );
}
clock_t uend = clock();
close (f);
printf("no sync() seconds:%lf writes per second:%lf \n",
((double)(uend-ustart))/(CLOCKS_PER_SEC),
((double)records)/((double)(uend-ustart))/(CLOCKS_PER_SEC));
}


int main(int argc, const char * argv[])
{
/* withoutSync();*/
withSync();
return 0;
}

-- 
You are receiving this mail because:
You are watching the assignee of the bug.