diff options
Diffstat (limited to 'src/readahead/readahead-collect.c')
| -rw-r--r-- | src/readahead/readahead-collect.c | 33 |
1 files changed, 28 insertions, 5 deletions
diff --git a/src/readahead/readahead-collect.c b/src/readahead/readahead-collect.c index 008ede3964..70e0f66eda 100644 --- a/src/readahead/readahead-collect.c +++ b/src/readahead/readahead-collect.c @@ -233,9 +233,26 @@ static int collect(const char *root) { bool on_ssd, on_btrfs; struct statfs sfs; usec_t not_after; + uint64_t previous_block_readahead; + bool previous_block_readahead_set = false; assert(root); + if (asprintf(&pack_fn, "%s/.readahead", root) < 0) { + log_error("Out of memory"); + r = -ENOMEM; + goto finish; + } + + /* If there's no pack file yet we lower the kernel readahead + * so that mincore() is accurate. If there is a pack file + * already we assume it is accurate enough so that kernel + * readahead is never triggered. */ + previous_block_readahead_set = + access(pack_fn, F_OK) < 0 && + block_get_readahead(root, &previous_block_readahead) >= 0 && + block_set_readahead(root, 8*1024) >= 0; + write_one_line_file("/proc/self/oom_score_adj", "1000"); if (ioprio_set(IOPRIO_WHO_PROCESS, getpid(), IOPRIO_PRIO_VALUE(IOPRIO_CLASS_IDLE, 0)) < 0) @@ -458,10 +475,7 @@ done: on_btrfs = statfs(root, &sfs) >= 0 && (long) sfs.f_type == (long) BTRFS_SUPER_MAGIC; log_debug("On btrfs: %s", yes_no(on_btrfs)); - asprintf(&pack_fn, "%s/.readahead", root); - asprintf(&pack_fn_new, "%s/.readahead.new", root); - - if (!pack_fn || !pack_fn_new) { + if (asprintf(&pack_fn_new, "%s/.readahead.new", root) < 0) { log_error("Out of memory"); r = -ENOMEM; goto finish; @@ -551,7 +565,6 @@ finish: fclose(pack); unlink(pack_fn_new); } - free(pack_fn_new); free(pack_fn); @@ -560,6 +573,16 @@ finish: hashmap_free(files); + if (previous_block_readahead_set) { + uint64_t bytes; + + /* Restore the original kernel readahead setting if we + * changed it, and nobody has overwritten it since + * yet. */ + if (block_get_readahead(root, &bytes) >= 0 && bytes == 8*1024) + block_set_readahead(root, previous_block_readahead); + } + return r; } |