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 Thanks for testing. The results look encouraging, but I'd also like to get rid of the regression mentioned in my previous message. Thanks, Rafael -- To unsubscribe from this list: send the line "unsubscribe kernel-testers" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
