| Message ID | 1467202586-13412-2-git-send-email-imunsie@au.ibm.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
Le 29/06/2016 14:16, Ian Munsie a écrit : > From: Ian Munsie <imunsie@au1.ibm.com> > > The Scheduled Process Area is allocated dynamically with enough pages to > fit at least as many processes as the AFU descriptor indicated. Since > the calculation is non-trivial, it does this by calculating how many > processes could fit in an allocation of a given order, and increasing > that order until it can fit enough processes or hits the maximum > supported size. > > Currently, it will start this search using a SPA of 2 pages instead of > 1. This can waste a page of memory if the AFU's maximum number of > supported processes was small enough to fit in one page. > > Fix the algorithm to start the search at 1 page. > > Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Reviewed-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
On 29/06/16 22:16, Ian Munsie wrote: > From: Ian Munsie <imunsie@au1.ibm.com> > > The Scheduled Process Area is allocated dynamically with enough pages to > fit at least as many processes as the AFU descriptor indicated. Since > the calculation is non-trivial, it does this by calculating how many > processes could fit in an allocation of a given order, and increasing > that order until it can fit enough processes or hits the maximum > supported size. > > Currently, it will start this search using a SPA of 2 pages instead of > 1. This can waste a page of memory if the AFU's maximum number of > supported processes was small enough to fit in one page. > > Fix the algorithm to start the search at 1 page. > > Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Makes sense. Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
On Wed, 2016-29-06 at 12:16:26 UTC, Ian Munsie wrote: > From: Ian Munsie <imunsie@au1.ibm.com> > > The Scheduled Process Area is allocated dynamically with enough pages to > fit at least as many processes as the AFU descriptor indicated. Since > the calculation is non-trivial, it does this by calculating how many > processes could fit in an allocation of a given order, and increasing > that order until it can fit enough processes or hits the maximum > supported size. > > Currently, it will start this search using a SPA of 2 pages instead of > 1. This can waste a page of memory if the AFU's maximum number of > supported processes was small enough to fit in one page. > > Fix the algorithm to start the search at 1 page. > > Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> > Reviewed-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> > Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/2224b6719b09052a9fbf29422a cheers
diff --git a/drivers/misc/cxl/native.c b/drivers/misc/cxl/native.c index e80d8f7..120c468 100644 --- a/drivers/misc/cxl/native.c +++ b/drivers/misc/cxl/native.c @@ -189,7 +189,7 @@ int cxl_alloc_spa(struct cxl_afu *afu) unsigned spa_size; /* Work out how many pages to allocate */ - afu->native->spa_order = 0; + afu->native->spa_order = -1; do { afu->native->spa_order++; spa_size = (1 << afu->native->spa_order) * PAGE_SIZE;