Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: [PATCH v11]: Hibernation: fix the number of pages used for hibernate/thaw buffering | Date | Wed, 25 Apr 2012 00:12:00 +0200 |
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On Tuesday, April 24, 2012, Bojan Smojver wrote: > On Mon, 2012-04-23 at 23:59 +0200, Rafael J. Wysocki wrote: > > Please resend it with a better changelog. I mean, please explain what > > the regression is and why it is being fixed this way. > > --------------------------------------- > Hibernation regression fix, since 3.2. > > Calculate the number of required free pages based on non-high memory > pages only, because that is where the buffers will come from. > > Commit 081a9d043c983f161b78fdc4671324d1342b86bc introduced a new buffer > page allocation logic during hibernation, in order to improve the > performance. The amount of pages allocated was calculated based on total > amount of pages available, although only non-high memory pages are > usable for this purpose. This caused hibernation code to attempt to over > allocate pages on platforms that have high memory, which led to hangs. > > A more elaborate patch, which also addressed other hibernation/thaw > issues, has been merged into linux-next, commit > e9cbc5a6270be7aa9c42d9b15293ba9ac7161262. > > Signed-off-by: Bojan Smojver <bojan@rexursive.com>
Applied to linux-pm/linux-next. Will push to Linus later this week.
Thanks, Rafael
> --- > kernel/power/swap.c | 33 +++++++++++++++++++++++++-------- > 1 files changed, 25 insertions(+), 8 deletions(-) > > diff --git a/kernel/power/swap.c b/kernel/power/swap.c > index 8742fd0..fdf834f 100644 > --- a/kernel/power/swap.c > +++ b/kernel/power/swap.c > @@ -51,6 +51,23 @@ > > #define MAP_PAGE_ENTRIES (PAGE_SIZE / sizeof(sector_t) - 1) > > +/* > + * Number of free pages that are not high. > + */ > +static inline unsigned long low_free_pages(void) > +{ > + return nr_free_pages() - nr_free_highpages(); > +} > + > +/* > + * Number of pages required to be kept free while writing the image. Always > + * half of all available low pages before the writing starts. > + */ > +static inline unsigned long reqd_free_pages(void) > +{ > + return low_free_pages() / 2; > +} > + > struct swap_map_page { > sector_t entries[MAP_PAGE_ENTRIES]; > sector_t next_swap; > @@ -72,7 +89,7 @@ struct swap_map_handle { > sector_t cur_swap; > sector_t first_sector; > unsigned int k; > - unsigned long nr_free_pages, written; > + unsigned long reqd_free_pages; > u32 crc32; > }; > > @@ -316,8 +333,7 @@ static int get_swap_writer(struct swap_map_handle *handle) > goto err_rel; > } > handle->k = 0; > - handle->nr_free_pages = nr_free_pages() >> 1; > - handle->written = 0; > + handle->reqd_free_pages = reqd_free_pages(); > handle->first_sector = handle->cur_swap; > return 0; > err_rel: > @@ -352,11 +368,11 @@ static int swap_write_page(struct swap_map_handle *handle, void *buf, > handle->cur_swap = offset; > handle->k = 0; > } > - if (bio_chain && ++handle->written > handle->nr_free_pages) { > + if (bio_chain && low_free_pages() <= handle->reqd_free_pages) { > error = hib_wait_on_bio_chain(bio_chain); > if (error) > goto out; > - handle->written = 0; > + handle->reqd_free_pages = reqd_free_pages(); > } > out: > return error; > @@ -618,7 +634,7 @@ static int save_image_lzo(struct swap_map_handle *handle, > * Adjust number of free pages after all allocations have been done. > * We don't want to run out of pages when writing. > */ > - handle->nr_free_pages = nr_free_pages() >> 1; > + handle->reqd_free_pages = reqd_free_pages(); > > /* > * Start the CRC32 thread. > --------------------------------------- > >
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