| Message ID | 20230303055133.28752-1-luoxueqin@kylinos.cn (mailing list archive) |
|---|---|
| State | Deferred, archived |
| Headers | show |
| Series | [v2] PM/hibernation: set the default image size for large memory | expand |
On Fri, Mar 3, 2023 at 6:51 AM Xueqin Luo <luoxueqin@kylinos.cn> wrote: > > From: xueqin Luo <luoxueqin@kylinos.cn> > > As computers have more and more memory, they can store larger and > larger images. This poses a problem. Let's take a 16GB computer as > an example. When the number of pre-allocated pages is greater than > 900,000 and smaller than image_size, the duration of S4 increases > with the number of saved pages. When the number of pre-allocated > pages reaches 1.2 million, the duration of S4 increases by 8-10s. Well, I'm not quite sure what the problem is from the description above. Can you please explain? > We found that the image size is generally more than 900,000 pages, > so we set the default size of image_size for 16GB and above > computers to 1 million pages, which can reduce the running time > of S4 under certain conditions. > > This is the test data for 5 hours after the computer is turned on: > > Original kernel begin: > > [2023-02-24 19:16:56] [ 46.105423][ 2] [ T3075] PM: hibernation entry > [2023-02-24 19:16:59] [ 47.632000][ 1] [ T3075] done (allocated > 959239 pages) > [2023-02-24 19:18:05] [ 56.987043][ 2] [ T3075] PM: hibernation exit > > Five hours later: > > [2023-02-25 00:22:48] [18069.651640][ 4] [ T7590] PM: hibernation entry > [2023-02-25 01:23:59] [21671.194049][ 0] [ T8563] done (allocated > 1228878 pages) > [2023-02-25 00:24:06] [18080.639889][ 2] [ T7590] PM: hibernation exit > > After 5h, you can see that the S4 takes 8s more time. > > Five hours later, the modified kernel test data: > > [2023-02-24 15:52:08] [18190.171183][ 7] [T11151] PM: hibernation entry > [2023-02-24 15:52:11] [18191.677021][ 7] [T11151] done (allocated > 792597 pages) > [2023-02-24 15:53:15] [18201.028488][ 2] [T11151] PM: hibernation exit > > You can see that after five hours, the time has changed little compared > to the initial test data. > > Signed-off-by: xueqin Luo <luoxueqin@kylinos.cn> > --- > > v3: modify some comments > > v2: add test data > > kernel/power/snapshot.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c > index cd8b7b35f1e8..fa3950b19849 100644 > --- a/kernel/power/snapshot.c > +++ b/kernel/power/snapshot.c > @@ -136,7 +136,14 @@ unsigned long image_size; > > void __init hibernate_image_size_init(void) > { > - image_size = ((totalram_pages() * 2) / 5) * PAGE_SIZE; > + /* The totalram pages() for a computer of 16 memory size is > + * equal to 4032990 pages. And according to our observation, > + * the average image size is less than 1 million pages. > + */ > + if (totalram_pages() < 4032990) > + image_size = ((totalram_pages() * 2) / 5) * PAGE_SIZE; > + else > + image_size = 1000000 * PAGE_SIZE; > } > > /* > -- > 2.25.1 >
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index cd8b7b35f1e8..fa3950b19849 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -136,7 +136,14 @@ unsigned long image_size; void __init hibernate_image_size_init(void) { - image_size = ((totalram_pages() * 2) / 5) * PAGE_SIZE; + /* The totalram pages() for a computer of 16 memory size is + * equal to 4032990 pages. And according to our observation, + * the average image size is less than 1 million pages. + */ + if (totalram_pages() < 4032990) + image_size = ((totalram_pages() * 2) / 5) * PAGE_SIZE; + else + image_size = 1000000 * PAGE_SIZE; } /*