improvement?
Posted by Anonymous on Sat 17th Jan 2015 23:19
raw | new post
modification of post by Anonymous (view diff)

20150113.21:13:21        wim | hi guys, after using tmux for a while it seems like it's using quite some memory (using 1.9a).
20150113.21:13:44        wim | 128Mb at the moment for 8 windows
20150113.21:14:31        wim | memory leak?

20150114.00:47:03       nicm | tmux returns memory to libc and is reliant on it to return it to the kernel
20150114.00:47:14       nicm | glibc does not do so very aggressively
20150114.00:47:19       nicm | this is a common issue on linux
20150114.00:47:48       nicm | there is a library call you can put into tmux if you want it to be returned more quickly
20150114.00:48:32       nicm | malloc_trim(3)
20150114.00:50:08       nicm | add malloc_trim(0) somewhere, server_second_callback in server.c would be a good place, or grid_destroy in grid.c
20150114.00:50:24       nicm | or just live with it and assume glibc knows best
20150114.00:51:23       nicm | i believe OS X is similar, if not worse, although it has different ways to reclaim the memory, i think it is kernel-side there

20150114.01:05:47        wim | nicm: nice! malloc_trim(0) works

20150114.01:11:55  freeroute | wim: are you running Linux? How did you get it working? Just add to source code?
20150114.01:12:12        wim | freeroute: yes and yes
20150114.01:12:35        wim | in grid_destroy()
20150114.01:12:35        wim |     free(gd);
20150114.01:12:35        wim |     malloc_trim(0);
20150114.01:12:45        wim | add it under the last free
20150114.01:14:41        wim | would be nice if it got into the code though :/


================================================================================================================================

So basically, in tmux/grid.c - you want it to look like this:

/* Destroy grid. */
void
grid_destroy(struct grid *gd)
{
        struct grid_line        *gl;
        u_int                    yy;

        for (yy = 0; yy < gd->hsize + gd->sy; yy++) {
                gl = &gd->linedata[yy];
                free(gl->celldata);
        }

        free(gd->linedata);

        free(gd);
        malloc_trim(0);
}

================================================================================================================================

:(

20150117.22:21:01        wim | nicm: is this something that could be merged? makes it portable? the malloc_trim thing -
                             | https://github.com/42wim/tmux/commit/429fc7a7498ca39c5210b26d4e541e8d6969db3a
20150117.22:24:42  freeroute | wim: does the code say like "If this is going to get compiled by glibc, then also include this code" and by 'this code' I mean that malloc_trim thing.
20150117.22:26:10  freeroute | if so then that means I can read C :D
20150117.22:26:59        wim | that's the gist of it yes
20150117.22:45:40       nicm | not really
20150117.22:46:45       nicm | it's up to glibc how malloc works really
20150117.22:52:26        wim | nicm: no power to the people instead of letting the system decide ? :-)
20150117.22:53:46        wim | nicm: i tried fiddling with the environment variables, but didn't get it to work as well as malloc_trim()
20150117.22:55:48       nicm | you need to talk to the glibc folks if their environment vars don't work
20150117.22:57:26       nicm | i don't think we should do this in the code
20150117.22:58:47        wim | ok thanks, was worth a try