On Wed, May 06, 2009 at 07:07:44AM +0800, Rafael J. Wysocki wrote: > On Tuesday 05 May 2009, Wu Fengguang wrote: > > On Tue, May 05, 2009 at 10:24:27AM +0800, Wu Fengguang wrote: > > > On Mon, May 04, 2009 at 08:22:38AM +0800, Rafael J. Wysocki wrote: > > > > From: Rafael J. Wysocki <rjw@xxxxxxx> > > > > > > > > Since the hibernation code is now going to use allocations of memory > > > > to create enough room for the image, it can also use the page frames > > > > allocated at this stage as image page frames. The low-level > > > > hibernation code needs to be rearranged for this purpose, but it > > > > allows us to avoid freeing a great number of pages and allocating > > > > these same pages once again later, so it generally is worth doing. > > > > > > > > [rev. 2: Change the strategy of preallocating memory to allocate as > > > > many pages as needed to get the right image size in one shot (the > > > > excessive allocated pages are released afterwards).] > > > > > > Rafael, I tried out your patches and found doubled memory shrink speed! > > > > > > [ 579.641781] PM: Preallocating image memory ... done (allocated 383900 pages, 128000 image pages kept) > > > [ 583.087875] PM: Allocated 1535600 kbytes in 3.43 seconds (447.69 MB/s) > > > > > For you reference, here is the free memory before/after > > > hibernate_preallocate_memory(): > > > > > > # free > > > total used free shared buffers cached > > > Mem: 1933 1917 15 0 0 1845 > > > -/+ buffers/cache: 72 1861 > > > Swap: 0 0 0 > > > > > > # free > > > total used free shared buffers cached > > > Mem: 1933 920 1012 0 0 356 > > > -/+ buffers/cache: 563 1369 > > > Swap: 0 0 0 > > > > > > It seems that the preallocated memory is not freed on -ENOMEM. > > > > Ah, this was my fault. > > > > I used to do this debugging trick: > > > > @@ -1207,7 +1207,7 @@ int hibernate_preallocate_memory(void) > > pages, size); > > swsusp_show_speed(&start, &stop, pages, "Allocated"); > > > > - return 0; > > + return -ENOMEM; > > > > err_out: > > printk(KERN_CONT "\n"); > > > > That "return -ENOMEM" should be "error = -ENOMEM" :-) > > > > Here is one more run: > > > > [ 194.016991] PM: Preallocating image memory ... done (allocated 383897 pages, 128000 image pages kept) > > [ 196.505999] PM: Allocated 1535588 kbytes in 2.47 seconds (621.69 MB/s) > > > > Now the free report is back to normal: > > > > # free > > total used free shared buffers cached > > Mem: 1933 74 1858 0 0 15 The above 'free' still exposed something wrong: only 74M memory are left, instead of image_size=500M memory. I'm prepared to test your updated patches :-) _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
