Hi Michael, On Wed, Apr 03, 2013 at 11:17:58AM +0200, Michael Kerrisk wrote: > Hello Minchan, > > On Mon, Mar 25, 2013 at 7:21 AM, Minchan Kim <[email protected]> wrote: > > These day, there are many platforms avaiable in the embedded market > > and they are smarter than kernel which has very limited information > > about working set so they want to involve memory management more heavily > > like android's lowmemory killer and ashmem or recent many lowmemory > > notifier(there was several trial for various company NOKIA, SAMSUNG, > > Linaro, Google ChromeOS, Redhat). > > > > One of the simple imagine scenario about userspace's intelligence is that > > platform can manage tasks as forground and backgroud so it would be > > better to reclaim background's task pages for end-user's *responsibility* > > although it has frequent referenced pages. > > > > This patch adds new knob "reclaim under proc/<pid>/" so task manager > > can reclaim any target process anytime, anywhere. It could give another > > method to platform for using memory efficiently. > > > > It can avoid process killing for getting free memory, which was really > > terrible experience because I lost my best score of game I had ever > > after I switch the phone call while I enjoyed the game. > > > > Writing 1 to /proc/pid/reclaim reclaims only file pages. > > Writing 2 to /proc/pid/reclaim reclaims only anonymous pages. > > Writing 3 to /proc/pid/reclaim reclaims all pages from target process. > > > > Signed-off-by: Minchan Kim <[email protected]> > > --- > > fs/proc/base.c | 3 ++ > > fs/proc/internal.h | 1 + > > fs/proc/task_mmu.c | 115 > > +++++++++++++++++++++++++++++++++++++++++++++++++++ > > include/linux/rmap.h | 4 ++ > > mm/Kconfig | 13 ++++++ > > mm/internal.h | 7 +--- > > mm/vmscan.c | 59 ++++++++++++++++++++++++++ > > 7 files changed, 196 insertions(+), 6 deletions(-) > > > > diff --git a/fs/proc/base.c b/fs/proc/base.c > > index 9b43ff77..ed83e85 100644 > > [...] > > > +#define RECLAIM_FILE (1 << 0) > > +#define RECLAIM_ANON (1 << 1) > > +#define RECLAIM_ALL (RECLAIM_FILE | RECLAIM_ANON) > > + > > +static ssize_t reclaim_write(struct file *file, const char __user *buf, > > + size_t count, loff_t *ppos) > > +{ > > + struct task_struct *task; > > + char buffer[PROC_NUMBUF]; > > + struct mm_struct *mm; > > + struct vm_area_struct *vma; > > + int type; > > + int rv; > > + > > + memset(buffer, 0, sizeof(buffer)); > > + if (count > sizeof(buffer) - 1) > > + count = sizeof(buffer) - 1; > > + if (copy_from_user(buffer, buf, count)) > > + return -EFAULT; > > + rv = kstrtoint(strstrip(buffer), 10, &type); > > + if (rv < 0) > > + return rv > > + if (type < RECLAIM_ALL || type > RECLAIM_FILE) > > + return -EINVAL;> + task = > > get_proc_task(file->f_path.dentry->d_inode); > > The check here is the wrong way round. Should be > > if (type < RECLAIM_FILE || type > RECLAIM_ALL) > > Thanks,
You give me a chance to remember "last minute change is really evil" Thanks! -- Kind regards, Minchan Kim -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
