diff options
Diffstat (limited to 'src/sort.c')
| -rw-r--r-- | src/sort.c | 34 |
1 files changed, 21 insertions, 13 deletions
diff --git a/src/sort.c b/src/sort.c index 6bce49b4e..54dd81528 100644 --- a/src/sort.c +++ b/src/sort.c @@ -659,9 +659,6 @@ proctab_comparator (void const *e1, void const *e2) /* The number of unreaped child processes. */ static pid_t nprocs; -/* The number of child processes we'll allow before we try to reap some. */ -enum { MAX_PROCS_BEFORE_REAP = 2 }; - static bool delete_proc (pid_t); /* If PID is positive, wait for the child process with that PID to @@ -743,12 +740,21 @@ wait_proc (pid_t pid) already exited. */ static void -reap_some (void) +reap_exited (void) { while (0 < nprocs && reap (0)) continue; } +/* Reap at least one exited child, waiting if necessary. */ + +static void +reap_some (void) +{ + reap (-1); + reap_exited (); +} + /* Reap all children, waiting if necessary. */ static void @@ -969,6 +975,16 @@ pipe_fork (int pipefds[2], size_t tries) if (pipe (pipefds) < 0) return -1; + /* At least NMERGE + 1 subprocesses are needed. More could be created, but + uncontrolled subprocess generation can hurt performance significantly. + Allow at most NMERGE + 2 subprocesses, on the theory that there + may be some useful parallelism by letting compression for the + previous merge finish (1 subprocess) in parallel with the current + merge (NMERGE + 1 subprocesses). */ + + if (nmerge + 1 < nprocs) + reap_some (); + while (tries--) { /* This is so the child process won't delete our temp files @@ -991,7 +1007,7 @@ pipe_fork (int pipefds[2], size_t tries) { xnanosleep (wait_retry); wait_retry *= 2; - reap_some (); + reap_exited (); } } @@ -2968,10 +2984,6 @@ mergefps (struct sortfile *files, size_t ntemps, size_t nfiles, ord[j] = ord[j + 1]; ord[count_of_smaller_lines] = ord0; } - - /* Free up some resources every once in a while. */ - if (MAX_PROCS_BEFORE_REAP < nprocs) - reap_some (); } if (unique && savedline) @@ -3829,10 +3841,6 @@ sort (char *const *files, size_t nfiles, char const *output_file, xfclose (tfp, temp_output); - /* Free up some resources every once in a while. */ - if (MAX_PROCS_BEFORE_REAP < nprocs) - reap_some (); - if (output_file_created) goto finish; } |