The following commit has been merged into the perf/core branch of tip: Commit-ID: 91feca5e2ecc9752894d57c9a72c2645471929c3 Gitweb: https://git.kernel.org/tip/91feca5e2ecc9752894d57c9a72c2645471929c3 Author: Alexander Shishkin <[email protected]> AuthorDate: Wed, 21 Aug 2019 15:47:26 +03:00 Committer: Ingo Molnar <[email protected]> CommitterDate: Mon, 26 Aug 2019 12:00:15 +02:00
perf/x86/intel/pt: Free up space in a ToPA descriptor Currently, we're storing physical address of a ToPA table in its descriptor, which is completely unnecessary. Since the descriptor and the table itself share the same page, reducing the descriptor size leaves more space for the table. Signed-off-by: Alexander Shishkin <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Vince Weaver <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- arch/x86/events/intel/pt.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/arch/x86/events/intel/pt.c b/arch/x86/events/intel/pt.c index 2e3f068..0f38ed3 100644 --- a/arch/x86/events/intel/pt.c +++ b/arch/x86/events/intel/pt.c @@ -548,14 +548,12 @@ static void pt_config_buffer(void *buf, unsigned int topa_idx, /** * struct topa - ToPA metadata * @list: linkage to struct pt_buffer's list of tables - * @phys: physical address of this page * @offset: offset of the first entry in this table in the buffer * @size: total size of all entries in this table * @last: index of the last initialized entry in this table */ struct topa { struct list_head list; - u64 phys; u64 offset; size_t size; int last; @@ -589,6 +587,11 @@ static inline struct topa_page *topa_entry_to_page(struct topa_entry *te) return (struct topa_page *)((unsigned long)te & PAGE_MASK); } +static inline phys_addr_t topa_pfn(struct topa *topa) +{ + return PFN_DOWN(virt_to_phys(topa_to_page(topa))); +} + /* make -1 stand for the last table entry */ #define TOPA_ENTRY(t, i) \ ((i) == -1 \ @@ -615,14 +618,13 @@ static struct topa *topa_alloc(int cpu, gfp_t gfp) tp = page_address(p); tp->topa.last = 0; - tp->topa.phys = page_to_phys(p); /* * In case of singe-entry ToPA, always put the self-referencing END * link as the 2nd entry in the table */ if (!intel_pt_validate_hw_cap(PT_CAP_topa_multiple_entries)) { - TOPA_ENTRY(&tp->topa, 1)->base = tp->topa.phys; + TOPA_ENTRY(&tp->topa, 1)->base = page_to_phys(p); TOPA_ENTRY(&tp->topa, 1)->end = 1; } @@ -666,7 +668,7 @@ static void topa_insert_table(struct pt_buffer *buf, struct topa *topa) BUG_ON(last->last != TENTS_PER_PAGE - 1); - TOPA_ENTRY(last, -1)->base = topa->phys >> TOPA_SHIFT; + TOPA_ENTRY(last, -1)->base = topa_pfn(topa); TOPA_ENTRY(last, -1)->end = 1; } @@ -739,8 +741,8 @@ static void pt_topa_dump(struct pt_buffer *buf) struct topa_page *tp = topa_to_page(topa); int i; - pr_debug("# table @%p (%016Lx), off %llx size %zx\n", tp->table, - topa->phys, topa->offset, topa->size); + pr_debug("# table @%p, off %llx size %zx\n", tp->table, + topa->offset, topa->size); for (i = 0; i < TENTS_PER_PAGE; i++) { pr_debug("# entry @%p (%lx sz %u %c%c%c) raw=%16llx\n", &tp->table[i], @@ -1111,7 +1113,7 @@ static int pt_buffer_init_topa(struct pt_buffer *buf, int cpu, /* link last table to the first one, unless we're double buffering */ if (intel_pt_validate_hw_cap(PT_CAP_topa_multiple_entries)) { - TOPA_ENTRY(buf->last, -1)->base = buf->first->phys >> TOPA_SHIFT; + TOPA_ENTRY(buf->last, -1)->base = topa_pfn(buf->first); TOPA_ENTRY(buf->last, -1)->end = 1; }
