On Mon, Apr 9, 2012 at 4:56 PM, David Rientjes <[email protected]> wrote: > The task handoff notifier leaks task_struct since it never gets freed > after the callback returns NOTIFY_OK, which means it is responsible for > doing so. > > It turns out the lowmemorykiller actually doesn't need this notifier at > all. It's used to prevent unnecessary killing by waiting for a thread to > exit as a result of lowmem_shrink(), however, it's possible to do this in > the same way the kernel oom killer works by setting TIF_MEMDIE and avoid > killing if we're still waiting for it to exit. > > The kernel oom killer will already automatically set TIF_MEMDIE for > threads that are attempting to allocate memory that have a fatal signal. > The thread selected by lowmem_shrink() will have such a signal after the > lowmemorykiller sends it a SIGKILL, so this won't result in an > unnecessary use of memory reserves for the thread to exit. > > This has the added benefit that we don't have to rely on CONFIG_PROFILING > to prevent needlessly killing tasks. > > Reported-by: werner <[email protected]> > Cc: [email protected] > Signed-off-by: David Rientjes <[email protected]> > --- > drivers/staging/android/lowmemorykiller.c | 48 > +++++------------------------ > 1 file changed, 7 insertions(+), 41 deletions(-) >
I did a quick test to measure the difference in time spent inside lowmem_shrink with and without this patch, and they were about the same. So, Acked-by: Colin Cross <[email protected]> -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
