The patch titled
gru: fix bug in allocation of kernel contexts
has been removed from the -mm tree. Its filename was
gru-fix-bug-in-allocation-of-kernel-contexts.patch
This patch was dropped because it was merged into mainline or a subsystem tree
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: gru: fix bug in allocation of kernel contexts
From: Jack Steiner <steiner@xxxxxxx>
Fix a bug in the assignment of GRU contexts used for kernel functions. If
a sleep occurs on the wait for a semaphore, the thread could switch cpus
and allocate resources on the wrong blade.
Signed-off-by: Jack Steiner <steiner@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/misc/sgi-gru/grukservices.c | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)
diff -puN drivers/misc/sgi-gru/grukservices.c~gru-fix-bug-in-allocation-of-kernel-contexts drivers/misc/sgi-gru/grukservices.c
--- a/drivers/misc/sgi-gru/grukservices.c~gru-fix-bug-in-allocation-of-kernel-contexts
+++ a/drivers/misc/sgi-gru/grukservices.c
@@ -221,13 +221,21 @@ static int gru_free_kernel_contexts(void
static struct gru_blade_state *gru_lock_kernel_context(int blade_id)
{
struct gru_blade_state *bs;
+ int bid;
STAT(lock_kernel_context);
- bs = gru_base[blade_id];
+again:
+ bid = blade_id < 0 ? uv_numa_blade_id() : blade_id;
+ bs = gru_base[bid];
+ /* Handle the case where migration occured while waiting for the sema */
down_read(&bs->bs_kgts_sema);
+ if (blade_id < 0 && bid != uv_numa_blade_id()) {
+ up_read(&bs->bs_kgts_sema);
+ goto again;
+ }
if (!bs->bs_kgts || !bs->bs_kgts->ts_gru)
- gru_load_kernel_context(bs, blade_id);
+ gru_load_kernel_context(bs, bid);
return bs;
}
@@ -256,7 +264,7 @@ static int gru_get_cpu_resources(int dsr
BUG_ON(dsr_bytes > GRU_NUM_KERNEL_DSR_BYTES);
preempt_disable();
- bs = gru_lock_kernel_context(uv_numa_blade_id());
+ bs = gru_lock_kernel_context(-1);
lcpu = uv_blade_processor_id();
*cb = bs->kernel_cb + lcpu * GRU_HANDLE_STRIDE;
*dsr = bs->kernel_dsr + lcpu * GRU_NUM_KERNEL_DSR_BYTES;
_
Patches currently in -mm which might be from steiner@xxxxxxx are
origin.patch
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