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gru: dynamic allocation of kernel contexts
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Change the interface to gru_alloc_gts() so that it can be used to allocate
GRU contexts for kernel threads.  Kernel threads do not have vdata
structures for the GRU contexts.  The GRU resource count are now passed
explicitly instead of inside the vdata structure.

Signed-off-by: Jack Steiner <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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@torvalds
Jack Steiner authored and torvalds committed Jun 18, 2009
1 parent 9cc9b05 commit 364b76d
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Showing 2 changed files with 33 additions and 29 deletions.
60 changes: 31 additions & 29 deletions drivers/misc/sgi-gru/grumain.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -299,15 +299,13 @@ static struct gru_thread_state *gru_find_current_gts_nolock(struct gru_vma_data
/*
* Allocate a thread state structure.
*/
static struct gru_thread_state *gru_alloc_gts(struct vm_area_struct *vma,
struct gru_vma_data *vdata,
int tsid)
struct gru_thread_state *gru_alloc_gts(struct vm_area_struct *vma,
int cbr_au_count, int dsr_au_count, int options, int tsid)
{
struct gru_thread_state *gts;
int bytes;

bytes = DSR_BYTES(vdata->vd_dsr_au_count) +
CBR_BYTES(vdata->vd_cbr_au_count);
bytes = DSR_BYTES(dsr_au_count) + CBR_BYTES(cbr_au_count);
bytes += sizeof(struct gru_thread_state);
gts = kzalloc(bytes, GFP_KERNEL);
if (!gts)
Expand All @@ -316,21 +314,22 @@ static struct gru_thread_state *gru_alloc_gts(struct vm_area_struct *vma,
STAT(gts_alloc);
atomic_set(&gts->ts_refcnt, 1);
mutex_init(&gts->ts_ctxlock);
gts->ts_cbr_au_count = vdata->vd_cbr_au_count;
gts->ts_dsr_au_count = vdata->vd_dsr_au_count;
gts->ts_user_options = vdata->vd_user_options;
gts->ts_cbr_au_count = cbr_au_count;
gts->ts_dsr_au_count = dsr_au_count;
gts->ts_user_options = options;
gts->ts_tsid = tsid;
gts->ts_user_options = vdata->vd_user_options;
gts->ts_ctxnum = NULLCTX;
gts->ts_mm = current->mm;
gts->ts_vma = vma;
gts->ts_tlb_int_select = -1;
gts->ts_gms = gru_register_mmu_notifier();
gts->ts_sizeavail = GRU_SIZEAVAIL(PAGE_SHIFT);
if (!gts->ts_gms)
goto err;
if (vma) {
gts->ts_mm = current->mm;
gts->ts_vma = vma;
gts->ts_gms = gru_register_mmu_notifier();
if (!gts->ts_gms)
goto err;
}

gru_dbg(grudev, "alloc vdata %p, new gts %p\n", vdata, gts);
gru_dbg(grudev, "alloc gts %p\n", gts);
return gts;

err:
Expand Down Expand Up @@ -381,7 +380,8 @@ struct gru_thread_state *gru_alloc_thread_state(struct vm_area_struct *vma,
struct gru_vma_data *vdata = vma->vm_private_data;
struct gru_thread_state *gts, *ngts;

gts = gru_alloc_gts(vma, vdata, tsid);
gts = gru_alloc_gts(vma, vdata->vd_cbr_au_count, vdata->vd_dsr_au_count,
vdata->vd_user_options, tsid);
if (!gts)
return NULL;

Expand Down Expand Up @@ -645,7 +645,7 @@ static int gru_retarget_intr(struct gru_thread_state *gts)
#define next_gru(b, g) (((g) < &(b)->bs_grus[GRU_CHIPLETS_PER_BLADE - 1]) ? \
((g)+1) : &(b)->bs_grus[0])

static void gru_steal_context(struct gru_thread_state *gts)
static void gru_steal_context(struct gru_thread_state *gts, int blade_id)
{
struct gru_blade_state *blade;
struct gru_state *gru, *gru0;
Expand All @@ -655,8 +655,7 @@ static void gru_steal_context(struct gru_thread_state *gts)
cbr = gts->ts_cbr_au_count;
dsr = gts->ts_dsr_au_count;

preempt_disable();
blade = gru_base[uv_numa_blade_id()];
blade = gru_base[blade_id];
spin_lock(&blade->bs_lock);

ctxnum = next_ctxnum(blade->bs_lru_ctxnum);
Expand Down Expand Up @@ -693,7 +692,6 @@ static void gru_steal_context(struct gru_thread_state *gts)
blade->bs_lru_gru = gru;
blade->bs_lru_ctxnum = ctxnum;
spin_unlock(&blade->bs_lock);
preempt_enable();

if (ngts) {
STAT(steal_context);
Expand All @@ -713,17 +711,17 @@ static void gru_steal_context(struct gru_thread_state *gts)
/*
* Scan the GRUs on the local blade & assign a GRU context.
*/
static struct gru_state *gru_assign_gru_context(struct gru_thread_state *gts)
static struct gru_state *gru_assign_gru_context(struct gru_thread_state *gts,
int blade)
{
struct gru_state *gru, *grux;
int i, max_active_contexts;

preempt_disable();

again:
gru = NULL;
max_active_contexts = GRU_NUM_CCH;
for_each_gru_on_blade(grux, uv_numa_blade_id(), i) {
for_each_gru_on_blade(grux, blade, i) {
if (check_gru_resources(grux, gts->ts_cbr_au_count,
gts->ts_dsr_au_count,
max_active_contexts)) {
Expand Down Expand Up @@ -763,7 +761,6 @@ static struct gru_state *gru_assign_gru_context(struct gru_thread_state *gts)
STAT(assign_context_failed);
}

preempt_enable();
return gru;
}

Expand All @@ -778,6 +775,7 @@ int gru_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
struct gru_thread_state *gts;
unsigned long paddr, vaddr;
int blade_id;

vaddr = (unsigned long)vmf->virtual_address;
gru_dbg(grudev, "vma %p, vaddr 0x%lx (0x%lx)\n",
Expand All @@ -792,8 +790,10 @@ int gru_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
again:
mutex_lock(&gts->ts_ctxlock);
preempt_disable();
blade_id = uv_numa_blade_id();

if (gts->ts_gru) {
if (gts->ts_gru->gs_blade_id != uv_numa_blade_id()) {
if (gts->ts_gru->gs_blade_id != blade_id) {
STAT(migrated_nopfn_unload);
gru_unload_context(gts, 1);
} else {
Expand All @@ -803,12 +803,14 @@ int gru_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
}

if (!gts->ts_gru) {
if (!gru_assign_gru_context(gts)) {
mutex_unlock(&gts->ts_ctxlock);
if (!gru_assign_gru_context(gts, blade_id)) {
preempt_enable();
mutex_unlock(&gts->ts_ctxlock);
set_current_state(TASK_INTERRUPTIBLE);
schedule_timeout(GRU_ASSIGN_DELAY); /* true hack ZZZ */
blade_id = uv_numa_blade_id();
if (gts->ts_steal_jiffies + GRU_STEAL_DELAY < jiffies)
gru_steal_context(gts);
gru_steal_context(gts, blade_id);
goto again;
}
gru_load_context(gts);
Expand All @@ -818,8 +820,8 @@ int gru_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
vma->vm_page_prot);
}

mutex_unlock(&gts->ts_ctxlock);
preempt_enable();
mutex_unlock(&gts->ts_ctxlock);

return VM_FAULT_NOPAGE;
}
Expand Down
2 changes: 2 additions & 0 deletions drivers/misc/sgi-gru/grutables.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -630,6 +630,8 @@ extern void gru_flush_all_tlb(struct gru_state *gru);
extern int gru_proc_init(void);
extern void gru_proc_exit(void);

extern struct gru_thread_state *gru_alloc_gts(struct vm_area_struct *vma,
int cbr_au_count, int dsr_au_count, int options, int tsid);
extern unsigned long gru_reserve_cb_resources(struct gru_state *gru,
int cbr_au_count, char *cbmap);
extern unsigned long gru_reserve_ds_resources(struct gru_state *gru,
Expand Down

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