-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 On 07/06/2016 01:10 PM, Franz Fellner wrote: > On Wed, 06 Jul 2016 15:06:20 +0000, James <[email protected]> wrote: >> Franz Fellner <alpine.art.de <at> gmail.com> writes: >> >> >>> I have issues with some prgrams eating too much memory. This seems to be >>> related to glibc not trimming as >>> necessary which results in way too much memory still occupied by the >>> program after free()ing memory. >> >> Perhaps you should file a bug, providing some evidence if other distros are >> affected (this suggests it might be a gcc issue) or other distros are not >> affected (this suggests it might be a gentoo pathch issue)? > > I mentioned my issues several times with the answer "can't be, the issue is > on your side". > When I filed a bug against tmux regarding its memory consumption I got told > "glibc is known to do bad things" and I was given this patch for tmux which > instantenously solved my issue: > > diff --git a/grid.c b/grid.c > index ef7c374..96385f4 100644 > --- a/grid.c > +++ b/grid.c > @@ -113,6 +113,8 @@ grid_destroy(struct grid *gd) > free(gd->linedata); > > > + > + malloc_trim(0); > } > > /* Compare grids. */ > @@ -326,6 +328,8 @@ grid_clear_lines(struct grid *gd, u_int py, u_int ny) > free(gl->celldata); > memset(gl, 0, sizeof *gl); > } > + > + malloc_trim(0); > } > > /* Move a group of lines. */ > > I have some other applications that are unusable to a certain degree. Having > to patch every single application isn't possible, I want to get to the root > of the issue :) And USE=vanilla is my first attempt. > > Thx > Franz >
Check out the mallopt(3) man page. You can fine-tune glibc heap through environment variables without patches. Specifically use MALLOC_TRIM_THRESHOLD_ to tell glibc when to trim and MALLOC_MMAP_THRESHOLD_ to tell it to use mmap() to allocate large chunks (so they're returned to the kernel when free()d). Just setting the trim treshold too low or calling malloc_trim(0) may be a bad idea. In some cases it will make your process numbers look better but hurt performance because malloc() will have to request memory from the kernel more often and on a system with swap it will just be swapped out if needed so it shouldn't be a problem unless it's a lot. And if it is a lot I think you should be looking somewhere else for the source of the problem. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBCAAGBQJXfVIcAAoJEPbOFX/5UlwcwT4P/RDvLd6zsvNulN7AYCvPYFr/ 2+BZmSSDeKJh5kbdGUzWb8FnqucAeFIBHYdpviEG7umDpZT6RN8MiFeDnK8W8Ww9 jLQyPgSXxTlfFNMGyxnJ/+EphSxPQ0LNjk98etHOKZNx6lM9NSN4kESRpk0LzSEs Qqp5WWipZU0kMqpfXZDr9U92MFLuSSe/LMRxuovIkz/tqlDHA1HTScob5CCAGmBx G4m1vxM7dPyv9YDAOELLR2y8CuoJzbiwhxOBAUBFJk3hF9Z1wDW0/8DbcogSwZkd T4mEQB28zEawjs0aguBXSKYemN3Nik1d1sPokZQ7SKCgVpIT0bHDV/cuoccTsWr0 eliobWgCzipXa15hvccU+xqSD25tZYX3f47T7/IMiwZW4CMFZZtY4X9BX/KTn7/C Q29M3ZM4NkbmSU27FtpKUQNl4/KrvMypmNBGcqb1BH74Y9Pay0Y9wHb+qeu8eITQ A07wgCJTtCm0s3dtyU7tu5SU6R2CSbJurJ9pvAHC1qNhQfCQYy3yxOEh0CCrCXC1 5nH94W1W1wjthJzYf728lvFloEpI7uT0RngpTJIR5Fg6Ku5ZA14rv8qANEbLEnTe hFV32a0cSbp3jMnUyvdYyxx89aOhJ08AU2Wf1L5DF5bMG864E5oH3AZc5a3OeNNu jJ+zTzNMF2lZ2ePZYcRg =ALKt -----END PGP SIGNATURE-----
