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| author | Alexey Dobriyan <adobriyan@gmail.com> | 2018-02-06 15:37:06 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-02-06 18:32:43 -0800 |
| commit | 20d28cde5558a2a211620254ec7bc53a4334167f (patch) | |
| tree | a582f9fb922b27400f251686ab8212825b8a9745 /fs/proc | |
| parent | 593bc695a1102a540f1613c651e73693b17a7343 (diff) | |
| download | linux-20d28cde5558a2a211620254ec7bc53a4334167f.tar.gz linux-20d28cde5558a2a211620254ec7bc53a4334167f.tar.bz2 linux-20d28cde5558a2a211620254ec7bc53a4334167f.zip | |
proc: less memory for /proc/*/map_files readdir
dentry name can be evaluated later, right before calling into VFS.
Also, spend less time under ->mmap_sem.
Link: http://lkml.kernel.org/r/20171110163034.GA2534@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/proc')
| -rw-r--r-- | fs/proc/base.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c index 4c12cb2cd704..a3efc2427c74 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2026,9 +2026,9 @@ out: } struct map_files_info { + unsigned long start; + unsigned long end; fmode_t mode; - unsigned int len; - unsigned char name[4*sizeof(long)+2]; /* max: %lx-%lx\0 */ }; /* @@ -2198,10 +2198,9 @@ proc_map_files_readdir(struct file *file, struct dir_context *ctx) if (++pos <= ctx->pos) continue; + info.start = vma->vm_start; + info.end = vma->vm_end; info.mode = vma->vm_file->f_mode; - info.len = snprintf(info.name, - sizeof(info.name), "%lx-%lx", - vma->vm_start, vma->vm_end); if (flex_array_put(fa, i++, &info, GFP_KERNEL)) BUG(); } @@ -2209,9 +2208,13 @@ proc_map_files_readdir(struct file *file, struct dir_context *ctx) up_read(&mm->mmap_sem); for (i = 0; i < nr_files; i++) { + char buf[4 * sizeof(long) + 2]; /* max: %lx-%lx\0 */ + unsigned int len; + p = flex_array_get(fa, i); + len = snprintf(buf, sizeof(buf), "%lx-%lx", p->start, p->end); if (!proc_fill_cache(file, ctx, - p->name, p->len, + buf, len, proc_map_files_instantiate, task, (void *)(unsigned long)p->mode)) |