Re: [PATCH v2] tools: copyfile: use 64k instead of 512 buffer

[Dragan Simic]

Hello Ahelenia,

Please see my comments below.

On 2024-03-21 19:29, Ahelenia Ziemiańska wrote:

This is a trivial but significant optimisation:

s/optimisation/optimization/

mkimage took >200ms (and 49489 writes (of which 49456 512)),
now it takes  110ms (and   419 writes (of which   386 64k)).

sendfile is much more appropriate for this and is done in one syscall,
but doesn't bring any significant speedups over 64k r/w
at the 13M size ranges, so there's no need to introduce
        #if __linux__
        while((size = sendfile(fd_dst, fd_src, NULL, 128 * 1024 * 1024)) > 0)
                ;
        if(size != -1) {
                ret = 0;
                goto out;
        }
        #endif

Also lift up the buffer size to a macro.

s/lift up/extract/
s/macro/constant/

Signed-off-by: Ahelenia Ziemiańska <nabijaczlew...@nabijaczleweli.xyz>
Reviewed-by: Dragan Simic <dsi...@manjaro.org>
---
 tools/fit_common.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/tools/fit_common.c b/tools/fit_common.c
index 2d417d47..1df4785c 100644
--- a/tools/fit_common.c
+++ b/tools/fit_common.c
@@ -127,6 +127,7 @@ err:

 int copyfile(const char *src, const char *dst)
 {
+#define copyfile_bufsize (64 * 1024)

This is not the right place for such a preprocessor directive.
Instead, it should be placed at the start of the file.

Also, it should use all uppercase letters.

        int fd_src = -1, fd_dst = -1;
        void *buf = NULL;
        ssize_t size;
@@ -145,14 +146,14 @@ int copyfile(const char *src, const char *dst)
                goto out;
        }

-       buf = calloc(1, 512);
+       buf = calloc(1, copyfile_bufsize);
        if (!buf) {
                printf("Can't allocate buffer to copy file\n");
                goto out;
        }

        while (1) {
-               size = read(fd_src, buf, 512);
+               size = read(fd_src, buf, copyfile_bufsize);
                if (size < 0) {
                        printf("Can't read file %s\n", src);
                        goto out;