| Message ID | 20191030013701.39647-1-almasrymina@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v8,1/9] hugetlb_cgroup: Add hugetlb_cgroup reservation counter | expand |
Cc: Andrew This series is getting closer to consideration for the mm tree. Mina, Be sure to cc Andrew with next version of series. On 10/29/19 6:36 PM, Mina Almasry wrote: > These counters will track hugetlb reservations rather than hugetlb > memory faulted in. This patch only adds the counter, following patches > add the charging and uncharging of the counter. I honestly am not sure the preferred method for including the overall design in a commit message. Certainly it should be in the first patch. Perhaps, say this is patch 1 of a 9 patch series here. > Problem: > Currently tasks attempting to allocate more hugetlb memory than is available get > a failure at mmap/shmget time. This is thanks to Hugetlbfs Reservations [1]. > However, if a task attempts to allocate hugetlb memory only more than its > hugetlb_cgroup limit allows, the kernel will allow the mmap/shmget call, > but will SIGBUS the task when it attempts to fault the memory in. > > We have developers interested in using hugetlb_cgroups, and they have expressed > dissatisfaction regarding this behavior. We'd like to improve this > behavior such that tasks violating the hugetlb_cgroup limits get an error on > mmap/shmget time, rather than getting SIGBUS'd when they try to fault > the excess memory in. > > The underlying problem is that today's hugetlb_cgroup accounting happens > at hugetlb memory *fault* time, rather than at *reservation* time. > Thus, enforcing the hugetlb_cgroup limit only happens at fault time, and > the offending task gets SIGBUS'd. > > Proposed Solution: > A new page counter named hugetlb.xMB.reservation_[limit|usage]_in_bytes. This > counter has slightly different semantics than > hugetlb.xMB.[limit|usage]_in_bytes: > > - While usage_in_bytes tracks all *faulted* hugetlb memory, > reservation_usage_in_bytes tracks all *reserved* hugetlb memory and > hugetlb memory faulted in without a prior reservation. > > - If a task attempts to reserve more memory than limit_in_bytes allows, > the kernel will allow it to do so. But if a task attempts to reserve > more memory than reservation_limit_in_bytes, the kernel will fail this > reservation. > > This proposal is implemented in this patch series, with tests to verify > functionality and show the usage. We also added cgroup-v2 support to > hugetlb_cgroup so that the new use cases can be extended to v2. > > Alternatives considered: > 1. A new cgroup, instead of only a new page_counter attached to > the existing hugetlb_cgroup. Adding a new cgroup seemed like a lot of code > duplication with hugetlb_cgroup. Keeping hugetlb related page counters under > hugetlb_cgroup seemed cleaner as well. > > 2. Instead of adding a new counter, we considered adding a sysctl that modifies > the behavior of hugetlb.xMB.[limit|usage]_in_bytes, to do accounting at > reservation time rather than fault time. Adding a new page_counter seems > better as userspace could, if it wants, choose to enforce different cgroups > differently: one via limit_in_bytes, and another via > reservation_limit_in_bytes. This could be very useful if you're > transitioning how hugetlb memory is partitioned on your system one > cgroup at a time, for example. Also, someone may find usage for both > limit_in_bytes and reservation_limit_in_bytes concurrently, and this > approach gives them the option to do so. > > Testing: I think that simply mentioning the use of hugetlbfs for regression testing would be sufficient here. > - Added tests passing. > - libhugetlbfs tests mostly passing, but some tests have trouble with and > without this patch series. Seems environment issue rather than code: > - Overall results: > ********** TEST SUMMARY > * 2M > * 32-bit 64-bit > * Total testcases: 84 0 > * Skipped: 0 0 > * PASS: 66 0 > * FAIL: 14 0 > * Killed by signal: 0 0 > * Bad configuration: 4 0 > * Expected FAIL: 0 0 > * Unexpected PASS: 0 0 > * Test not present: 0 0 > * Strange test result: 0 0 > ********** It is curious that you only ran the tests for 32 bit applications. Certainly the more common case today is 64 bit. I don't think there are any surprises for you as I also have been running hugetlbfs on this series.
On Thu, Nov 7, 2019 at 3:42 PM Mike Kravetz <mike.kravetz@oracle.com> wrote: > > Cc: Andrew > This series is getting closer to consideration for the mm tree. > Mina, > Be sure to cc Andrew with next version of series. > Absolutely! > On 10/29/19 6:36 PM, Mina Almasry wrote: > > These counters will track hugetlb reservations rather than hugetlb > > memory faulted in. This patch only adds the counter, following patches > > add the charging and uncharging of the counter. > > I honestly am not sure the preferred method for including the overall > design in a commit message. Certainly it should be in the first patch. > Perhaps, say this is patch 1 of a 9 patch series here. > Will do. I read somewhere I can't find right now it's better this way so that the useful information becomes part of the git log. If anyone has strong opinions on this I'll just go back to putting it into a cover letter. > > Problem: > > Currently tasks attempting to allocate more hugetlb memory than is available get > > a failure at mmap/shmget time. This is thanks to Hugetlbfs Reservations [1]. > > However, if a task attempts to allocate hugetlb memory only more than its > > hugetlb_cgroup limit allows, the kernel will allow the mmap/shmget call, > > but will SIGBUS the task when it attempts to fault the memory in. > > > > We have developers interested in using hugetlb_cgroups, and they have expressed > > dissatisfaction regarding this behavior. We'd like to improve this > > behavior such that tasks violating the hugetlb_cgroup limits get an error on > > mmap/shmget time, rather than getting SIGBUS'd when they try to fault > > the excess memory in. > > > > The underlying problem is that today's hugetlb_cgroup accounting happens > > at hugetlb memory *fault* time, rather than at *reservation* time. > > Thus, enforcing the hugetlb_cgroup limit only happens at fault time, and > > the offending task gets SIGBUS'd. > > > > Proposed Solution: > > A new page counter named hugetlb.xMB.reservation_[limit|usage]_in_bytes. This > > counter has slightly different semantics than > > hugetlb.xMB.[limit|usage]_in_bytes: > > > > - While usage_in_bytes tracks all *faulted* hugetlb memory, > > reservation_usage_in_bytes tracks all *reserved* hugetlb memory and > > hugetlb memory faulted in without a prior reservation. > > > > - If a task attempts to reserve more memory than limit_in_bytes allows, > > the kernel will allow it to do so. But if a task attempts to reserve > > more memory than reservation_limit_in_bytes, the kernel will fail this > > reservation. > > > > This proposal is implemented in this patch series, with tests to verify > > functionality and show the usage. We also added cgroup-v2 support to > > hugetlb_cgroup so that the new use cases can be extended to v2. > > > > Alternatives considered: > > 1. A new cgroup, instead of only a new page_counter attached to > > the existing hugetlb_cgroup. Adding a new cgroup seemed like a lot of code > > duplication with hugetlb_cgroup. Keeping hugetlb related page counters under > > hugetlb_cgroup seemed cleaner as well. > > > > 2. Instead of adding a new counter, we considered adding a sysctl that modifies > > the behavior of hugetlb.xMB.[limit|usage]_in_bytes, to do accounting at > > reservation time rather than fault time. Adding a new page_counter seems > > better as userspace could, if it wants, choose to enforce different cgroups > > differently: one via limit_in_bytes, and another via > > reservation_limit_in_bytes. This could be very useful if you're > > transitioning how hugetlb memory is partitioned on your system one > > cgroup at a time, for example. Also, someone may find usage for both > > limit_in_bytes and reservation_limit_in_bytes concurrently, and this > > approach gives them the option to do so. > > > > Testing: > > I think that simply mentioning the use of hugetlbfs for regression testing > would be sufficient here. > Will do. > > - Added tests passing. > > - libhugetlbfs tests mostly passing, but some tests have trouble with and > > without this patch series. Seems environment issue rather than code: > > - Overall results: > > ********** TEST SUMMARY > > * 2M > > * 32-bit 64-bit > > * Total testcases: 84 0 > > * Skipped: 0 0 > > * PASS: 66 0 > > * FAIL: 14 0 > > * Killed by signal: 0 0 > > * Bad configuration: 4 0 > > * Expected FAIL: 0 0 > > * Unexpected PASS: 0 0 > > * Test not present: 0 0 > > * Strange test result: 0 0 > > ********** > > It is curious that you only ran the tests for 32 bit applications. Certainly > the more common case today is 64 bit. I don't think there are any surprises > for you as I also have been running hugetlbfs on this series. I did run them, with similar results. I'll add them. > -- > Mike Kravetz > > > - Failing tests: > > - elflink_rw_and_share_test("linkhuge_rw") segfaults with and without this > > patch series. > > - LD_PRELOAD=libhugetlbfs.so HUGETLB_MORECORE=yes malloc (2M: 32): > > FAIL Address is not hugepage > > - LD_PRELOAD=libhugetlbfs.so HUGETLB_RESTRICT_EXE=unknown:malloc > > HUGETLB_MORECORE=yes malloc (2M: 32): > > FAIL Address is not hugepage > > - LD_PRELOAD=libhugetlbfs.so HUGETLB_MORECORE=yes malloc_manysmall (2M: 32): > > FAIL Address is not hugepage > > - GLIBC_TUNABLES=glibc.malloc.tcache_count=0 LD_PRELOAD=libhugetlbfs.so > > HUGETLB_MORECORE=yes heapshrink (2M: 32): > > FAIL Heap not on hugepages > > - GLIBC_TUNABLES=glibc.malloc.tcache_count=0 LD_PRELOAD=libhugetlbfs.so > > libheapshrink.so HUGETLB_MORECORE=yes heapshrink (2M: 32): > > FAIL Heap not on hugepages > > - HUGETLB_ELFMAP=RW linkhuge_rw (2M: 32): FAIL small_data is not hugepage > > - HUGETLB_ELFMAP=RW HUGETLB_MINIMAL_COPY=no linkhuge_rw (2M: 32): > > FAIL small_data is not hugepage > > - alloc-instantiate-race shared (2M: 32): > > Bad configuration: sched_setaffinity(cpu1): Invalid argument - > > FAIL Child 1 killed by signal Killed > > - shmoverride_linked (2M: 32): > > FAIL shmget failed size 2097152 from line 176: Invalid argument > > - HUGETLB_SHM=yes shmoverride_linked (2M: 32): > > FAIL shmget failed size 2097152 from line 176: Invalid argument > > - shmoverride_linked_static (2M: 32): > > FAIL shmget failed size 2097152 from line 176: Invalid argument > > - HUGETLB_SHM=yes shmoverride_linked_static (2M: 32): > > FAIL shmget failed size 2097152 from line 176: Invalid argument > > - LD_PRELOAD=libhugetlbfs.so shmoverride_unlinked (2M: 32): > > FAIL shmget failed size 2097152 from line 176: Invalid argument > > - LD_PRELOAD=libhugetlbfs.so HUGETLB_SHM=yes shmoverride_unlinked (2M: 32): > > FAIL shmget failed size 2097152 from line 176: Invalid argument > > > > [1]: https://www.kernel.org/doc/html/latest/vm/hugetlbfs_reserv.html > > > > Signed-off-by: Mina Almasry <almasrymina@google.com> > > Acked-by: Hillf Danton <hdanton@sina.com>
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 53fc34f930d08..9c49a0ba894d3 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -320,6 +320,27 @@ unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, #ifdef CONFIG_HUGETLB_PAGE +enum { + /* Tracks hugetlb memory faulted in. */ + HUGETLB_RES_USAGE, + /* Tracks hugetlb memory reserved. */ + HUGETLB_RES_RESERVATION_USAGE, + /* Limit for hugetlb memory faulted in. */ + HUGETLB_RES_LIMIT, + /* Limit for hugetlb memory reserved. */ + HUGETLB_RES_RESERVATION_LIMIT, + /* Max usage for hugetlb memory faulted in. */ + HUGETLB_RES_MAX_USAGE, + /* Max usage for hugetlb memory reserved. */ + HUGETLB_RES_RESERVATION_MAX_USAGE, + /* Faulted memory accounting fail count. */ + HUGETLB_RES_FAILCNT, + /* Reserved memory accounting fail count. */ + HUGETLB_RES_RESERVATION_FAILCNT, + HUGETLB_RES_NULL, + HUGETLB_RES_MAX, +}; + #define HSTATE_NAME_LEN 32 /* Defines one hugetlb page size */ struct hstate { @@ -340,7 +361,7 @@ struct hstate { unsigned int surplus_huge_pages_node[MAX_NUMNODES]; #ifdef CONFIG_CGROUP_HUGETLB /* cgroup control files */ - struct cftype cgroup_files[5]; + struct cftype cgroup_files[HUGETLB_RES_MAX]; #endif char name[HSTATE_NAME_LEN]; }; diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c index f1930fa0b445d..1ed4448ca41d3 100644 --- a/mm/hugetlb_cgroup.c +++ b/mm/hugetlb_cgroup.c @@ -25,6 +25,10 @@ struct hugetlb_cgroup { * the counter to account for hugepages from hugetlb. */ struct page_counter hugepage[HUGE_MAX_HSTATE]; + /* + * the counter to account for hugepage reservations from hugetlb. + */ + struct page_counter reserved_hugepage[HUGE_MAX_HSTATE]; }; #define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val)) @@ -33,6 +37,14 @@ struct hugetlb_cgroup { static struct hugetlb_cgroup *root_h_cgroup __read_mostly; +static inline struct page_counter * +hugetlb_cgroup_get_counter(struct hugetlb_cgroup *h_cg, int idx, bool reserved) +{ + if (reserved) + return &h_cg->reserved_hugepage[idx]; + return &h_cg->hugepage[idx]; +} + static inline struct hugetlb_cgroup *hugetlb_cgroup_from_css(struct cgroup_subsys_state *s) { @@ -254,30 +266,33 @@ void hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages, return; } -enum { - RES_USAGE, - RES_LIMIT, - RES_MAX_USAGE, - RES_FAILCNT, -}; - static u64 hugetlb_cgroup_read_u64(struct cgroup_subsys_state *css, struct cftype *cft) { struct page_counter *counter; + struct page_counter *reserved_counter; struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(css); counter = &h_cg->hugepage[MEMFILE_IDX(cft->private)]; + reserved_counter = &h_cg->reserved_hugepage[MEMFILE_IDX(cft->private)]; switch (MEMFILE_ATTR(cft->private)) { - case RES_USAGE: + case HUGETLB_RES_USAGE: return (u64)page_counter_read(counter) * PAGE_SIZE; - case RES_LIMIT: + case HUGETLB_RES_RESERVATION_USAGE: + return (u64)page_counter_read(reserved_counter) * PAGE_SIZE; + case HUGETLB_RES_LIMIT: return (u64)counter->max * PAGE_SIZE; - case RES_MAX_USAGE: + case HUGETLB_RES_RESERVATION_LIMIT: + return (u64)reserved_counter->max * PAGE_SIZE; + case HUGETLB_RES_MAX_USAGE: return (u64)counter->watermark * PAGE_SIZE; - case RES_FAILCNT: + case HUGETLB_RES_RESERVATION_MAX_USAGE: + return (u64)reserved_counter->watermark * PAGE_SIZE; + case HUGETLB_RES_FAILCNT: return counter->failcnt; + case HUGETLB_RES_RESERVATION_FAILCNT: + return reserved_counter->failcnt; default: BUG(); } @@ -291,6 +306,7 @@ static ssize_t hugetlb_cgroup_write(struct kernfs_open_file *of, int ret, idx; unsigned long nr_pages; struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(of_css(of)); + bool reserved = false; if (hugetlb_cgroup_is_root(h_cg)) /* Can't set limit on root */ return -EINVAL; @@ -304,9 +320,14 @@ static ssize_t hugetlb_cgroup_write(struct kernfs_open_file *of, nr_pages = round_down(nr_pages, 1 << huge_page_order(&hstates[idx])); switch (MEMFILE_ATTR(of_cft(of)->private)) { - case RES_LIMIT: + case HUGETLB_RES_RESERVATION_LIMIT: + reserved = true; + /* Fall through. */ + case HUGETLB_RES_LIMIT: mutex_lock(&hugetlb_limit_mutex); - ret = page_counter_set_max(&h_cg->hugepage[idx], nr_pages); + ret = page_counter_set_max(hugetlb_cgroup_get_counter(h_cg, idx, + reserved), + nr_pages); mutex_unlock(&hugetlb_limit_mutex); break; default: @@ -320,18 +341,26 @@ static ssize_t hugetlb_cgroup_reset(struct kernfs_open_file *of, char *buf, size_t nbytes, loff_t off) { int ret = 0; - struct page_counter *counter; + struct page_counter *counter, *reserved_counter; struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(of_css(of)); counter = &h_cg->hugepage[MEMFILE_IDX(of_cft(of)->private)]; + reserved_counter = + &h_cg->reserved_hugepage[MEMFILE_IDX(of_cft(of)->private)]; switch (MEMFILE_ATTR(of_cft(of)->private)) { - case RES_MAX_USAGE: + case HUGETLB_RES_MAX_USAGE: page_counter_reset_watermark(counter); break; - case RES_FAILCNT: + case HUGETLB_RES_RESERVATION_MAX_USAGE: + page_counter_reset_watermark(reserved_counter); + break; + case HUGETLB_RES_FAILCNT: counter->failcnt = 0; break; + case HUGETLB_RES_RESERVATION_FAILCNT: + reserved_counter->failcnt = 0; + break; default: ret = -EINVAL; break; @@ -357,37 +386,67 @@ static void __init __hugetlb_cgroup_file_init(int idx) struct hstate *h = &hstates[idx]; /* format the size */ - mem_fmt(buf, 32, huge_page_size(h)); + mem_fmt(buf, sizeof(buf), huge_page_size(h)); /* Add the limit file */ - cft = &h->cgroup_files[0]; + cft = &h->cgroup_files[HUGETLB_RES_LIMIT]; snprintf(cft->name, MAX_CFTYPE_NAME, "%s.limit_in_bytes", buf); - cft->private = MEMFILE_PRIVATE(idx, RES_LIMIT); + cft->private = MEMFILE_PRIVATE(idx, HUGETLB_RES_LIMIT); + cft->read_u64 = hugetlb_cgroup_read_u64; + cft->write = hugetlb_cgroup_write; + + /* Add the reservation limit file */ + cft = &h->cgroup_files[HUGETLB_RES_RESERVATION_LIMIT]; + snprintf(cft->name, MAX_CFTYPE_NAME, "%s.reservation_limit_in_bytes", + buf); + cft->private = MEMFILE_PRIVATE(idx, HUGETLB_RES_RESERVATION_LIMIT); cft->read_u64 = hugetlb_cgroup_read_u64; cft->write = hugetlb_cgroup_write; /* Add the usage file */ - cft = &h->cgroup_files[1]; + cft = &h->cgroup_files[HUGETLB_RES_USAGE]; snprintf(cft->name, MAX_CFTYPE_NAME, "%s.usage_in_bytes", buf); - cft->private = MEMFILE_PRIVATE(idx, RES_USAGE); + cft->private = MEMFILE_PRIVATE(idx, HUGETLB_RES_USAGE); + cft->read_u64 = hugetlb_cgroup_read_u64; + + /* Add the reservation usage file */ + cft = &h->cgroup_files[HUGETLB_RES_RESERVATION_USAGE]; + snprintf(cft->name, MAX_CFTYPE_NAME, "%s.reservation_usage_in_bytes", + buf); + cft->private = MEMFILE_PRIVATE(idx, HUGETLB_RES_RESERVATION_USAGE); cft->read_u64 = hugetlb_cgroup_read_u64; /* Add the MAX usage file */ - cft = &h->cgroup_files[2]; + cft = &h->cgroup_files[HUGETLB_RES_MAX_USAGE]; snprintf(cft->name, MAX_CFTYPE_NAME, "%s.max_usage_in_bytes", buf); - cft->private = MEMFILE_PRIVATE(idx, RES_MAX_USAGE); + cft->private = MEMFILE_PRIVATE(idx, HUGETLB_RES_MAX_USAGE); + cft->write = hugetlb_cgroup_reset; + cft->read_u64 = hugetlb_cgroup_read_u64; + + /* Add the MAX reservation usage file */ + cft = &h->cgroup_files[HUGETLB_RES_RESERVATION_MAX_USAGE]; + snprintf(cft->name, MAX_CFTYPE_NAME, + "%s.reservation_max_usage_in_bytes", buf); + cft->private = MEMFILE_PRIVATE(idx, HUGETLB_RES_RESERVATION_MAX_USAGE); cft->write = hugetlb_cgroup_reset; cft->read_u64 = hugetlb_cgroup_read_u64; /* Add the failcntfile */ - cft = &h->cgroup_files[3]; + cft = &h->cgroup_files[HUGETLB_RES_FAILCNT]; snprintf(cft->name, MAX_CFTYPE_NAME, "%s.failcnt", buf); - cft->private = MEMFILE_PRIVATE(idx, RES_FAILCNT); + cft->private = MEMFILE_PRIVATE(idx, HUGETLB_RES_FAILCNT); + cft->write = hugetlb_cgroup_reset; + cft->read_u64 = hugetlb_cgroup_read_u64; + + /* Add the reservation failcntfile */ + cft = &h->cgroup_files[HUGETLB_RES_RESERVATION_FAILCNT]; + snprintf(cft->name, MAX_CFTYPE_NAME, "%s.reservation_failcnt", buf); + cft->private = MEMFILE_PRIVATE(idx, HUGETLB_RES_RESERVATION_FAILCNT); cft->write = hugetlb_cgroup_reset; cft->read_u64 = hugetlb_cgroup_read_u64; /* NULL terminate the last cft */ - cft = &h->cgroup_files[4]; + cft = &h->cgroup_files[HUGETLB_RES_NULL]; memset(cft, 0, sizeof(*cft)); WARN_ON(cgroup_add_legacy_cftypes(&hugetlb_cgrp_subsys,
These counters will track hugetlb reservations rather than hugetlb memory faulted in. This patch only adds the counter, following patches add the charging and uncharging of the counter. Problem: Currently tasks attempting to allocate more hugetlb memory than is available get a failure at mmap/shmget time. This is thanks to Hugetlbfs Reservations [1]. However, if a task attempts to allocate hugetlb memory only more than its hugetlb_cgroup limit allows, the kernel will allow the mmap/shmget call, but will SIGBUS the task when it attempts to fault the memory in. We have developers interested in using hugetlb_cgroups, and they have expressed dissatisfaction regarding this behavior. We'd like to improve this behavior such that tasks violating the hugetlb_cgroup limits get an error on mmap/shmget time, rather than getting SIGBUS'd when they try to fault the excess memory in. The underlying problem is that today's hugetlb_cgroup accounting happens at hugetlb memory *fault* time, rather than at *reservation* time. Thus, enforcing the hugetlb_cgroup limit only happens at fault time, and the offending task gets SIGBUS'd. Proposed Solution: A new page counter named hugetlb.xMB.reservation_[limit|usage]_in_bytes. This counter has slightly different semantics than hugetlb.xMB.[limit|usage]_in_bytes: - While usage_in_bytes tracks all *faulted* hugetlb memory, reservation_usage_in_bytes tracks all *reserved* hugetlb memory and hugetlb memory faulted in without a prior reservation. - If a task attempts to reserve more memory than limit_in_bytes allows, the kernel will allow it to do so. But if a task attempts to reserve more memory than reservation_limit_in_bytes, the kernel will fail this reservation. This proposal is implemented in this patch series, with tests to verify functionality and show the usage. We also added cgroup-v2 support to hugetlb_cgroup so that the new use cases can be extended to v2. Alternatives considered: 1. A new cgroup, instead of only a new page_counter attached to the existing hugetlb_cgroup. Adding a new cgroup seemed like a lot of code duplication with hugetlb_cgroup. Keeping hugetlb related page counters under hugetlb_cgroup seemed cleaner as well. 2. Instead of adding a new counter, we considered adding a sysctl that modifies the behavior of hugetlb.xMB.[limit|usage]_in_bytes, to do accounting at reservation time rather than fault time. Adding a new page_counter seems better as userspace could, if it wants, choose to enforce different cgroups differently: one via limit_in_bytes, and another via reservation_limit_in_bytes. This could be very useful if you're transitioning how hugetlb memory is partitioned on your system one cgroup at a time, for example. Also, someone may find usage for both limit_in_bytes and reservation_limit_in_bytes concurrently, and this approach gives them the option to do so. Testing: - Added tests passing. - libhugetlbfs tests mostly passing, but some tests have trouble with and without this patch series. Seems environment issue rather than code: - Overall results: ********** TEST SUMMARY * 2M * 32-bit 64-bit * Total testcases: 84 0 * Skipped: 0 0 * PASS: 66 0 * FAIL: 14 0 * Killed by signal: 0 0 * Bad configuration: 4 0 * Expected FAIL: 0 0 * Unexpected PASS: 0 0 * Test not present: 0 0 * Strange test result: 0 0 ********** - Failing tests: - elflink_rw_and_share_test("linkhuge_rw") segfaults with and without this patch series. - LD_PRELOAD=libhugetlbfs.so HUGETLB_MORECORE=yes malloc (2M: 32): FAIL Address is not hugepage - LD_PRELOAD=libhugetlbfs.so HUGETLB_RESTRICT_EXE=unknown:malloc HUGETLB_MORECORE=yes malloc (2M: 32): FAIL Address is not hugepage - LD_PRELOAD=libhugetlbfs.so HUGETLB_MORECORE=yes malloc_manysmall (2M: 32): FAIL Address is not hugepage - GLIBC_TUNABLES=glibc.malloc.tcache_count=0 LD_PRELOAD=libhugetlbfs.so HUGETLB_MORECORE=yes heapshrink (2M: 32): FAIL Heap not on hugepages - GLIBC_TUNABLES=glibc.malloc.tcache_count=0 LD_PRELOAD=libhugetlbfs.so libheapshrink.so HUGETLB_MORECORE=yes heapshrink (2M: 32): FAIL Heap not on hugepages - HUGETLB_ELFMAP=RW linkhuge_rw (2M: 32): FAIL small_data is not hugepage - HUGETLB_ELFMAP=RW HUGETLB_MINIMAL_COPY=no linkhuge_rw (2M: 32): FAIL small_data is not hugepage - alloc-instantiate-race shared (2M: 32): Bad configuration: sched_setaffinity(cpu1): Invalid argument - FAIL Child 1 killed by signal Killed - shmoverride_linked (2M: 32): FAIL shmget failed size 2097152 from line 176: Invalid argument - HUGETLB_SHM=yes shmoverride_linked (2M: 32): FAIL shmget failed size 2097152 from line 176: Invalid argument - shmoverride_linked_static (2M: 32): FAIL shmget failed size 2097152 from line 176: Invalid argument - HUGETLB_SHM=yes shmoverride_linked_static (2M: 32): FAIL shmget failed size 2097152 from line 176: Invalid argument - LD_PRELOAD=libhugetlbfs.so shmoverride_unlinked (2M: 32): FAIL shmget failed size 2097152 from line 176: Invalid argument - LD_PRELOAD=libhugetlbfs.so HUGETLB_SHM=yes shmoverride_unlinked (2M: 32): FAIL shmget failed size 2097152 from line 176: Invalid argument [1]: https://www.kernel.org/doc/html/latest/vm/hugetlbfs_reserv.html Signed-off-by: Mina Almasry <almasrymina@google.com> Acked-by: Hillf Danton <hdanton@sina.com> --- include/linux/hugetlb.h | 23 ++++++++- mm/hugetlb_cgroup.c | 111 ++++++++++++++++++++++++++++++---------- 2 files changed, 107 insertions(+), 27 deletions(-) -- 2.24.0.rc1.363.gb1bccd3e3d-goog