[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen master] xen/x86: p2m-pod: Fix coding style for comments
commit 06e64f17fc9aeca2e1736088282635349344e00e Author: Julien Grall <julien.grall@xxxxxxx> AuthorDate: Mon Oct 2 16:40:01 2017 +0100 Commit: George Dunlap <george.dunlap@xxxxxxxxxx> CommitDate: Mon Oct 2 16:40:01 2017 +0100 xen/x86: p2m-pod: Fix coding style for comments Signed-off-by: Julien Grall <julien.grall@xxxxxxx> Acked-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> Reviewed-by: George Dunlap <george.dunlap@xxxxxxxxxx> Reviewed-by: Wei Liu <wei.liu2@xxxxxxxxxx> --- xen/arch/x86/mm/p2m-pod.c | 150 ++++++++++++++++++++++++++++++---------------- 1 file changed, 100 insertions(+), 50 deletions(-) diff --git a/xen/arch/x86/mm/p2m-pod.c b/xen/arch/x86/mm/p2m-pod.c index 1f07441..6beb26b 100644 --- a/xen/arch/x86/mm/p2m-pod.c +++ b/xen/arch/x86/mm/p2m-pod.c @@ -155,8 +155,10 @@ static struct page_info * p2m_pod_cache_get(struct p2m_domain *p2m, BUG_ON( page_list_empty(&p2m->pod.super) ); - /* Break up a superpage to make single pages. NB count doesn't - * need to be adjusted. */ + /* + * Break up a superpage to make single pages. NB count doesn't + * need to be adjusted. + */ p = page_list_remove_head(&p2m->pod.super); mfn = mfn_x(page_to_mfn(p)); @@ -242,8 +244,10 @@ p2m_pod_set_cache_target(struct p2m_domain *p2m, unsigned long pod_target, int p } /* Decreasing the target */ - /* We hold the pod lock here, so we don't need to worry about - * cache disappearing under our feet. */ + /* + * We hold the pod lock here, so we don't need to worry about + * cache disappearing under our feet. + */ while ( pod_target < p2m->pod.count ) { struct page_info * page; @@ -345,15 +349,19 @@ p2m_pod_set_mem_target(struct domain *d, unsigned long target) if ( d->is_dying ) goto out; - /* T' < B: Don't reduce the cache size; let the balloon driver - * take care of it. */ + /* + * T' < B: Don't reduce the cache size; let the balloon driver + * take care of it. + */ if ( target < d->tot_pages ) goto out; pod_target = target - populated; - /* B < T': Set the cache size equal to # of outstanding entries, - * let the balloon driver fill in the rest. */ + /* + * B < T': Set the cache size equal to # of outstanding entries, + * let the balloon driver fill in the rest. + */ if ( populated > 0 && pod_target > p2m->pod.entry_count ) pod_target = p2m->pod.entry_count; @@ -491,7 +499,8 @@ static int p2m_pod_zero_check_superpage(struct p2m_domain *p2m, unsigned long gfn); -/* This function is needed for two reasons: +/* + * This function is needed for two reasons: * + To properly handle clearing of PoD entries * + To "steal back" memory being freed for the PoD cache, rather than * releasing it. @@ -513,8 +522,10 @@ p2m_pod_decrease_reservation(struct domain *d, gfn_lock(p2m, gpfn, order); pod_lock(p2m); - /* If we don't have any outstanding PoD entries, let things take their - * course */ + /* + * If we don't have any outstanding PoD entries, let things take their + * course. + */ if ( p2m->pod.entry_count == 0 ) goto out_unlock; @@ -550,8 +561,10 @@ p2m_pod_decrease_reservation(struct domain *d, if ( !nonpod ) { - /* All PoD: Mark the whole region invalid and tell caller - * we're done. */ + /* + * All PoD: Mark the whole region invalid and tell caller + * we're done. + */ p2m_set_entry(p2m, gpfn, INVALID_MFN, order, p2m_invalid, p2m->default_access); p2m->pod.entry_count-=(1<<order); @@ -576,7 +589,8 @@ p2m_pod_decrease_reservation(struct domain *d, ASSERT(steal_for_cache == (p2m->pod.entry_count > p2m->pod.count)); } - /* Process as long as: + /* + * Process as long as: * + There are PoD entries to handle, or * + There is ram left, and we want to steal it */ @@ -631,8 +645,10 @@ p2m_pod_decrease_reservation(struct domain *d, } } - /* If there are no more non-PoD entries, tell decrease_reservation() that - * there's nothing left to do. */ + /* + * If there are no more non-PoD entries, tell decrease_reservation() that + * there's nothing left to do. + */ if ( nonpod == 0 ) ret = 1; @@ -658,9 +674,11 @@ void p2m_pod_dump_data(struct domain *d) } -/* Search for all-zero superpages to be reclaimed as superpages for the +/* + * Search for all-zero superpages to be reclaimed as superpages for the * PoD cache. Must be called w/ pod lock held, must lock the superpage - * in the p2m */ + * in the p2m. + */ static int p2m_pod_zero_check_superpage(struct p2m_domain *p2m, unsigned long gfn) { @@ -682,12 +700,16 @@ p2m_pod_zero_check_superpage(struct p2m_domain *p2m, unsigned long gfn) if ( paging_mode_shadow(d) ) max_ref++; - /* NOTE: this is why we don't enforce deadlock constraints between p2m - * and pod locks */ + /* + * NOTE: this is why we don't enforce deadlock constraints between p2m + * and pod locks. + */ gfn_lock(p2m, gfn, SUPERPAGE_ORDER); - /* Look up the mfns, checking to make sure they're the same mfn - * and aligned, and mapping them. */ + /* + * Look up the mfns, checking to make sure they're the same mfn + * and aligned, and mapping them. + */ for ( i = 0; i < SUPERPAGE_PAGES; i += n ) { p2m_access_t a; @@ -697,7 +719,8 @@ p2m_pod_zero_check_superpage(struct p2m_domain *p2m, unsigned long gfn) mfn = p2m->get_entry(p2m, gfn + i, &type, &a, 0, &cur_order, NULL); - /* Conditions that must be met for superpage-superpage: + /* + * Conditions that must be met for superpage-superpage: * + All gfns are ram types * + All gfns have the same type * + All of the mfns are allocated to a domain @@ -751,9 +774,11 @@ p2m_pod_zero_check_superpage(struct p2m_domain *p2m, unsigned long gfn) p2m_populate_on_demand, p2m->default_access); p2m_tlb_flush_sync(p2m); - /* Make none of the MFNs are used elsewhere... for example, mapped + /* + * Make none of the MFNs are used elsewhere... for example, mapped * via the grant table interface, or by qemu. Allow one refcount for - * being allocated to the domain. */ + * being allocated to the domain. + */ for ( i=0; i < SUPERPAGE_PAGES; i++ ) { mfn = _mfn(mfn_x(mfn0) + i); @@ -797,8 +822,10 @@ p2m_pod_zero_check_superpage(struct p2m_domain *p2m, unsigned long gfn) __trace_var(TRC_MEM_POD_ZERO_RECLAIM, 0, sizeof(t), &t); } - /* Finally! We've passed all the checks, and can add the mfn superpage - * back on the PoD cache, and account for the new p2m PoD entries */ + /* + * Finally! We've passed all the checks, and can add the mfn superpage + * back on the PoD cache, and account for the new p2m PoD entries. + */ p2m_pod_cache_add(p2m, mfn_to_page(mfn0), PAGE_ORDER_2M); p2m->pod.entry_count += SUPERPAGE_PAGES; @@ -833,8 +860,10 @@ p2m_pod_zero_check(struct p2m_domain *p2m, unsigned long *gfns, int count) { p2m_access_t a; mfns[i] = p2m->get_entry(p2m, gfns[i], types + i, &a, 0, NULL, NULL); - /* If this is ram, and not a pagetable or from the xen heap, and probably not mapped - elsewhere, map it; otherwise, skip. */ + /* + * If this is ram, and not a pagetable or from the xen heap, and + * probably not mapped elsewhere, map it; otherwise, skip. + */ if ( p2m_is_ram(types[i]) && ( (mfn_to_page(mfns[i])->count_info & PGC_allocated) != 0 ) && ( (mfn_to_page(mfns[i])->count_info & (PGC_page_table|PGC_xen_heap)) == 0 ) @@ -844,8 +873,10 @@ p2m_pod_zero_check(struct p2m_domain *p2m, unsigned long *gfns, int count) map[i] = NULL; } - /* Then, go through and check for zeroed pages, removing write permission - * for those with zeroes. */ + /* + * Then, go through and check for zeroed pages, removing write permission + * for those with zeroes. + */ for ( i=0; i<count; i++ ) { if(!map[i]) @@ -867,8 +898,10 @@ p2m_pod_zero_check(struct p2m_domain *p2m, unsigned long *gfns, int count) p2m_set_entry(p2m, gfns[i], INVALID_MFN, PAGE_ORDER_4K, p2m_populate_on_demand, p2m->default_access); - /* See if the page was successfully unmapped. (Allow one refcount - * for being allocated to a domain.) */ + /* + * See if the page was successfully unmapped. (Allow one refcount + * for being allocated to a domain.) + */ if ( (mfn_to_page(mfns[i])->count_info & PGC_count_mask) > 1 ) { unmap_domain_page(map[i]); @@ -895,8 +928,10 @@ p2m_pod_zero_check(struct p2m_domain *p2m, unsigned long *gfns, int count) unmap_domain_page(map[i]); - /* See comment in p2m_pod_zero_check_superpage() re gnttab - * check timing. */ + /* + * See comment in p2m_pod_zero_check_superpage() re gnttab + * check timing. + */ if ( j < PAGE_SIZE/sizeof(*map[i]) ) { p2m_set_entry(p2m, gfns[i], mfns[i], PAGE_ORDER_4K, @@ -944,9 +979,11 @@ p2m_pod_emergency_sweep(struct p2m_domain *p2m) limit = (start > POD_SWEEP_LIMIT) ? (start - POD_SWEEP_LIMIT) : 0; /* FIXME: Figure out how to avoid superpages */ - /* NOTE: Promote to globally locking the p2m. This will get complicated + /* + * NOTE: Promote to globally locking the p2m. This will get complicated * in a fine-grained scenario. If we lock each gfn individually we must be - * careful about spinlock recursion limits and POD_SWEEP_STRIDE. */ + * careful about spinlock recursion limits and POD_SWEEP_STRIDE. + */ p2m_lock(p2m); for ( i=p2m->pod.reclaim_single; i > 0 ; i-- ) { @@ -963,11 +1000,13 @@ p2m_pod_emergency_sweep(struct p2m_domain *p2m) j = 0; } } - /* Stop if we're past our limit and we have found *something*. + /* + * Stop if we're past our limit and we have found *something*. * * NB that this is a zero-sum game; we're increasing our cache size * by re-increasing our 'debt'. Since we hold the pod lock, - * (entry_count - count) must remain the same. */ + * (entry_count - count) must remain the same. + */ if ( i < limit && (p2m->pod.count > 0 || hypercall_preempt_check()) ) break; } @@ -1045,20 +1084,25 @@ p2m_pod_demand_populate(struct p2m_domain *p2m, unsigned long gfn, ASSERT(gfn_locked_by_me(p2m, gfn)); pod_lock(p2m); - /* This check is done with the pod lock held. This will make sure that + /* + * This check is done with the pod lock held. This will make sure that * even if d->is_dying changes under our feet, p2m_pod_empty_cache() - * won't start until we're done. */ + * won't start until we're done. + */ if ( unlikely(d->is_dying) ) goto out_fail; - /* Because PoD does not have cache list for 1GB pages, it has to remap - * 1GB region to 2MB chunks for a retry. */ + /* + * Because PoD does not have cache list for 1GB pages, it has to remap + * 1GB region to 2MB chunks for a retry. + */ if ( order == PAGE_ORDER_1G ) { pod_unlock(p2m); gfn_aligned = (gfn >> order) << order; - /* Note that we are supposed to call p2m_set_entry() 512 times to + /* + * Note that we are supposed to call p2m_set_entry() 512 times to * split 1GB into 512 2MB pages here. But We only do once here because * p2m_set_entry() should automatically shatter the 1GB page into * 512 2MB pages. The rest of 511 calls are unnecessary. @@ -1075,8 +1119,10 @@ p2m_pod_demand_populate(struct p2m_domain *p2m, unsigned long gfn, if ( p2m->pod.entry_count > p2m->pod.count ) pod_eager_reclaim(p2m); - /* Only sweep if we're actually out of memory. Doing anything else - * causes unnecessary time and fragmentation of superpages in the p2m. */ + /* + * Only sweep if we're actually out of memory. Doing anything else + * causes unnecessary time and fragmentation of superpages in the p2m. + */ if ( p2m->pod.count == 0 ) p2m_pod_emergency_sweep(p2m); @@ -1088,8 +1134,10 @@ p2m_pod_demand_populate(struct p2m_domain *p2m, unsigned long gfn, if ( gfn > p2m->pod.max_guest ) p2m->pod.max_guest = gfn; - /* Get a page f/ the cache. A NULL return value indicates that the - * 2-meg range should be marked singleton PoD, and retried */ + /* + * Get a page f/ the cache. A NULL return value indicates that the + * 2-meg range should be marked singleton PoD, and retried. + */ if ( (p = p2m_pod_cache_get(p2m, order)) == NULL ) goto remap_and_retry; @@ -1146,8 +1194,10 @@ remap_and_retry: pod_unlock(p2m); /* Remap this 2-meg region in singleton chunks */ - /* NOTE: In a p2m fine-grained lock scenario this might - * need promoting the gfn lock from gfn->2M superpage */ + /* + * NOTE: In a p2m fine-grained lock scenario this might + * need promoting the gfn lock from gfn->2M superpage. + */ gfn_aligned = (gfn>>order)<<order; for(i=0; i<(1<<order); i++) p2m_set_entry(p2m, gfn_aligned + i, INVALID_MFN, PAGE_ORDER_4K, -- generated by git-patchbot for /home/xen/git/xen.git#master _______________________________________________ Xen-changelog mailing list Xen-changelog@xxxxxxxxxxxxx https://lists.xenproject.org/xen-changelog
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