svlogd: fix performance problems: excessive write,

gettimeofday calls. rt_sigprocmask were dealt with
in previous commit

diff --git a/runit/svlogd.c b/runit/svlogd.c
index a0e562b..f0e9aaf 100644 (file)
--- a/runit/svlogd.c
+++ b/runit/svlogd.c
@@ -59,7 +59,7 @@ static iopause_fd input;
 static int fl_flag_0;
 
 static struct logdir {
-////   char *btmp;
+       ////char *btmp;
        /* pattern list to match, in "aa\0bb\0\cc\0\0" form */
        char *inst;
        char *processor;
@@ -73,6 +73,7 @@ static struct logdir {
        int ppid;
        int fddir;
        int fdcur;
+       FILE* filecur; ////
        int fdlock;
        struct taia trotate;
        char fnsave[FMT_PTIME];
@@ -300,11 +301,13 @@ static unsigned rotate(struct logdir *ld)
        }
 
        if (ld->size > 0) {
-               while (fsync(ld->fdcur) == -1)
+               while (fflush(ld->filecur) || fsync(ld->fdcur) == -1)
                        pause2cannot("fsync current logfile", ld->name);
                while (fchmod(ld->fdcur, 0744) == -1)
                        pause2cannot("set mode of current", ld->name);
-               close(ld->fdcur);
+               ////close(ld->fdcur);
+               fclose(ld->filecur);
+
                if (verbose) {
                        bb_error_msg(INFO"rename: %s/current %s %u", ld->name,
                                        ld->fnsave, ld->size);
@@ -313,6 +316,9 @@ static unsigned rotate(struct logdir *ld)
                        pause2cannot("rename current", ld->name);
                while ((ld->fdcur = open("current", O_WRONLY|O_NDELAY|O_APPEND|O_CREAT, 0600)) == -1)
                        pause2cannot("create new current", ld->name);
+               /* we presume this cannot fail */
+               ld->filecur = fdopen(ld->fdcur, "a"); ////
+               setvbuf(ld->filecur, NULL, _IOFBF, linelen); ////
                coe(ld->fdcur);
                ld->size = 0;
                while (fchmod(ld->fdcur, 0644) == -1)
@@ -337,7 +343,12 @@ static int buffer_pwrite(int n, char *s, unsigned len)
                if (len > (ld->sizemax - ld->size))
                        len = ld->sizemax - ld->size;
        }
-       while ((i = full_write(ld->fdcur, s, len)) == -1) {
+       while (1) {
+               ////i = full_write(ld->fdcur, s, len);
+               ////if (i != -1) break;
+               i = fwrite(s, 1, len, ld->filecur);
+               if (i == len) break;
+
                if ((errno == ENOSPC) && (ld->nmin < ld->nmax)) {
                        DIR *d;
                        struct dirent *f;
@@ -399,11 +410,12 @@ static void logdir_close(struct logdir *ld)
        ld->fddir = -1;
        if (ld->fdcur == -1)
                return; /* impossible */
-       while (fsync(ld->fdcur) == -1)
+       while (fflush(ld->filecur) || fsync(ld->fdcur) == -1)
                pause2cannot("fsync current logfile", ld->name);
        while (fchmod(ld->fdcur, 0744) == -1)
                pause2cannot("set mode of current", ld->name);
-       close(ld->fdcur);
+       ////close(ld->fdcur);
+       fclose(ld->filecur);
        ld->fdcur = -1;
        if (ld->fdlock == -1)
                return; /* impossible */
@@ -560,6 +572,10 @@ static unsigned logdir_open(struct logdir *ld, const char *fn)
        }
        while ((ld->fdcur = open("current", O_WRONLY|O_NDELAY|O_APPEND|O_CREAT, 0600)) == -1)
                pause2cannot("open current", ld->name);
+       /* we presume this cannot fail */
+       ld->filecur = fdopen(ld->fdcur, "a"); ////
+       setvbuf(ld->filecur, NULL, _IOFBF, linelen); ////
+
        coe(ld->fdcur);
        while (fchmod(ld->fdcur, 0644) == -1)
                pause2cannot("set mode of current", ld->name);
@@ -601,9 +617,8 @@ static ssize_t ndelay_read(int fd, void *buf, size_t count)
 }
 
 /* Used for reading stdin */
-static int buffer_pread(int fd, char *s, unsigned len)
+static int buffer_pread(int fd, char *s, unsigned len, struct taia *now)
 {
-       struct taia now;
        int i;
 
        if (rotateasap) {
@@ -620,12 +635,11 @@ static int buffer_pread(int fd, char *s, unsigned len)
                logdirs_reopen();
                reopenasap = 0;
        }
-       taia_now(&now);
        taia_uint(&trotate, 2744);
-       taia_add(&trotate, &now, &trotate);
+       taia_add(&trotate, now, &trotate);
        for (i = 0; i < dirn; ++i)
                if (dir[i].tmax) {
-                       if (taia_less(&dir[i].trotate, &now))
+                       if (taia_less(&dir[i].trotate, now))
                                rotate(dir+i);
                        if (taia_less(&dir[i].trotate, &trotate))
                                trotate = dir[i].trotate;
@@ -633,7 +647,7 @@ static int buffer_pread(int fd, char *s, unsigned len)
 
        while (1) {
                sigprocmask(SIG_UNBLOCK, &blocked_sigset, NULL);
-               iopause(&input, 1, &trotate, &now);
+               iopause(&input, 1, &trotate, now);
                sigprocmask(SIG_BLOCK, &blocked_sigset, NULL);
                i = ndelay_read(fd, s, len);
                if (i >= 0) break;
@@ -734,7 +748,6 @@ static void logmatch(struct logdir *ld)
 
 int svlogd_main(int argc, char **argv)
 {
-       struct taia now;
        char *r,*l,*b;
        ssize_t stdin_cnt = 0;
        int i;
@@ -757,10 +770,10 @@ int svlogd_main(int argc, char **argv)
                if (linemax == 0) linemax = BUFSIZ-26;
                if (linemax < 256) linemax = 256;
        }
-////   if (opt & 8) { // -b
-////           buflen = xatoi_u(b);
-////           if (buflen == 0) buflen = 1024;
-////   }
+       ////if (opt & 8) { // -b
+       ////    buflen = xatoi_u(b);
+       ////    if (buflen == 0) buflen = 1024;
+       ////}
        //if (opt & 0x10) timestamp++; // -t
        //if (opt & 0x20) verbose++; // -v
        //if (timestamp > 2) timestamp = 2;
@@ -807,8 +820,11 @@ int svlogd_main(int argc, char **argv)
        if (!timestamp)
                memRchr = memrchr;
 
+       setvbuf(stderr, NULL, _IOFBF, linelen);
+
        /* Each iteration processes one or more lines */
        while (1) {
+               struct taia now;
                char stamp[FMT_PTIME];
                char *lineptr;
                char *printptr;
@@ -817,9 +833,9 @@ int svlogd_main(int argc, char **argv)
                char ch;
 
                lineptr = line;
+               taia_now(&now);
                /* Prepare timestamp if needed */
                if (timestamp) {
-                       taia_now(&now);
                        switch (timestamp) {
                        case 1:
                                fmt_taia25(stamp, &now);
@@ -839,7 +855,7 @@ int svlogd_main(int argc, char **argv)
                if (!np && !exitasap) {
                        i = linemax - stdin_cnt; /* avail. bytes at tail */
                        if (i >= 128) {
-                               i = buffer_pread(0, lineptr + stdin_cnt, i);
+                               i = buffer_pread(0, lineptr + stdin_cnt, i, &now);
                                if (i <= 0) /* EOF or error on stdin */
                                        exitasap = 1;
                                else {
@@ -861,10 +877,10 @@ int svlogd_main(int argc, char **argv)
                /* linelen == no of chars incl. '\n' (or == stdin_cnt) */
                ch = lineptr[linelen-1];
 
-               /* TODO: biggest performance hit is coming from the fact
-                * that we do not buffer writes. We may read many lines
-                * in one read() above, but will do one write()
-                * per line below. Should we use stdio? */
+               /* Biggest performance hit was coming from the fact
+                * that we did not buffer writes. We were reading many lines
+                * in one read() above, but wrote one line per write().
+                * We are using stdio to fix that */
 
                /* write out lineptr[0..linelen-1] to each log destination
                 * (or lineptr[-26..linelen-1] if timestamping) */
@@ -882,7 +898,8 @@ int svlogd_main(int argc, char **argv)
                        if (ld->inst)
                                logmatch(ld);
                        if (ld->matcherr == 'e')
-                               full_write(2, printptr, printlen);
+                               ////full_write(2, printptr, printlen);
+                               fwrite(lineptr, 1, linelen, stderr);
                        if (ld->match != '+') continue;
                        buffer_pwrite(i, printptr, printlen);
                }
@@ -891,7 +908,8 @@ int svlogd_main(int argc, char **argv)
                /* read/write repeatedly until we see it */
                while (ch != '\n') {
                        /* lineptr is emptied now, safe to use as buffer */
-                       stdin_cnt = exitasap ? -1 : buffer_pread(0, lineptr, linemax);
+                       taia_now(&now);
+                       stdin_cnt = exitasap ? -1 : buffer_pread(0, lineptr, linemax, &now);
                        if (stdin_cnt <= 0) { /* EOF or error on stdin */
                                exitasap = 1;
                                lineptr[0] = ch = '\n';
@@ -908,7 +926,8 @@ int svlogd_main(int argc, char **argv)
                        for (i = 0; i < dirn; ++i) {
                                if (dir[i].fddir == -1) continue;
                                if (dir[i].matcherr == 'e')
-                                       full_write(2, lineptr, linelen);
+                                       ////full_write(2, lineptr, linelen);
+                                       fwrite(lineptr, 1, linelen, stderr);
                                if (dir[i].match != '+') continue;
                                buffer_pwrite(i, lineptr, linelen);
                        }
@@ -925,6 +944,7 @@ int svlogd_main(int argc, char **argv)
                        /* Move unprocessed data to the front of line */
                        memmove((timestamp ? line+26 : line), lineptr, stdin_cnt);
                }
+               fflush(NULL);////
        }
 
        for (i = 0; i < dirn; ++i) {